Digital BW, The Print

As I promised,there goes the comment from Dan about this issue...

Andr\ufffd writes,

>>I've been following the thread about 8 x 16 bits editing,and a question
came
to my mind? Are the considerations you made valid for BW images, or can we
severely degrade the image doing tonalmanipulations in 8 bits/pixel?>>

-Dan's answer:

Technically there is more of a case for 16-bit in B/W than in color images,
however it's unlikely to make any real difference.

Bit depth works along the same lines, although it doesn't have nearly as
pronounced an effect as, resolution. The higher the resolution of the
original capture, the more pixels have to be averaged to achieve final
output. This results in more smoothness, more consistency--if that's what
you
really need. It results in oversoftness, lack of focus, if it's not.
Similarly, less resolution provides a crisper, snappier look, if that's what
you want, or a harsh and jagged look if it isn't.

One can vary resolution quite a bit without hurting anything but it's
definitely possible to scan at a resolution that is so high that it actually
harms quality, just as it is to scan at a resolution so low that the result
will be disagreeable.

Varying bit depth has a similar effect, but much less of it. That is,
pictures corrected in 8-bit will, if the correction was very aggressive,
seem
very slightly sharper than those done in 16-bit. While the difference is
basically inconsequential, if we held a gun to people's head and forced them
to choose between two color images, most of the time, if they saw a
difference at all, they would choose the one corrected in 8-bit. Some of the
time, of course, they'd choose the 16-bit version.

In color, having extra channels softens the image, taking away some of the
16-bit advantage. If one channel is extra harsh it's not such a big deal. In
B/W, this effect doesn't exist, so there would be a lot more cases where one
might have a slight preference for a 16-bit correction.

Dan Margulis

> -Dan's answer:
>
> Technically there is more of a case for 16-bit in B/W than in
> color images,
> however it's unlikely to make any real difference.

I find Dan's comments on this topic quite wrong.  Doing tonal moves in 8
bit, CAN make a REAL difference.  It's a fact.

Here's one of the rubs of this issue.  If you select 8 bit data from the
scanner, the scanner driver typically does the tonal corrections TO high bit
data, then converts the high bit data to 8 bit data and sends you the
corrected 8 bit data, so you don't have to do much tonal correcting in PS,
if any, unless you want to "mess-up" your image.

So, how do you get 8 bit data out of the scanner to do your tonal
corrections to it in the first place?  On my scanner, I would have to scan
in 16 bit raw, and once in PS, set the setpoints, and then convert it to 8
bit data...the do tonal corrections to it.

If you don't quite understand the implications of that, and why all that
matters, let me know and I can explain further...

> Bit depth works along the same lines, although it doesn't have nearly as
> pronounced an effect as, resolution.

That is not true, especially as a blanket statement.  It depends on the
output image size for resolution.  Resolution change from 1k to 4k SPI may
have no effect on a smaller print, but a huge effect on a larger print, as
well as it's certainly film size dependant.

Doing tonal changes in 8 bits can wipe out ranges of tones completely, or
can have little effect...it is very image dependant, and it is also image
size dependant.  I am assuming this discussion is limited to images of
sufficient size (say a minimum of 8 x 8, 8 x 10 or larger) such that the
image displays a large enough print area for you to see the full range of
tonality from a decent viewing distance.

> Similarly, less resolution provides a crisper, snappier look, if
> that's what
> you want, or a harsh and jagged look if it isn't.

And it also means your image is less accurate...since there is dropped
information in the reproduced image.  You lose detail, whether it's "crisper
and/or snappier" or not.  A line-art image is "crisper and/or snappier" but
contains no real detail.

> One can vary resolution quite a bit without hurting anything

Only on small images, that, again, is a very inaccurate blanket statement.
Scanning at anything but the optical resolution of the scanner (except in
the case of grain aliasing) WILL degrade the image.

> Varying bit depth has a similar effect, but much less of it. That is,
> pictures corrected in 8-bit will, if the correction was very aggressive,
> seem
> very slightly sharper than those done in 16-bit.

Hum, that's again, not necessarily true.  It wouldn't necessarily seem
sharper.  It depends on what, exactly, you do.  What happens when you do
tonal corrections in an 8 bit space, is you ALWAYS lose tones, that is if
the original image contained all 256 tones in the first place.  A lot of
pixels that used to have different values, will now have the same value...
An example is taking four pixels, values 100, 101, 102 and 103.  Performing
a move on them so every pixel with the values 100-103 now all have the value
103.  You just dropped three tones out of four...and if that happened over
the entire tonal range, you'd have 64 tones, instead of 256.

When you do tonal corrections, you are doing one of three things.  You are
compressing a region, which loses tonal values as shown above, changing the
white and/or black endpoints (set points, and it's really a compression
too), which also loses tonal values or you are expanding a region....which
doesn't necessarily lose pixel values, the expansion has to compress some
other region...

If the lost tones are in a region of tonality (or a region of the image) you
don't care about, OR, especially more the case, are tones that there aren't
many pixels of that tonality, it won't have as drastic a visual effect.  It
all depends on what quality of output you want, and where the dropped tones
lie.

> ...In
> B/W, this effect doesn't exist, so there would be a lot more
> cases where one
> might have a slight preference for a 16-bit correction.

"slight preference"...well, it's far more than a "slight preference".  I
think the issue is strongly masked by the fact that most people get their
tonality set in the scanner driver, which, as I said above, does the tonal
move on high bit data.  After getting the data in PS, they only do small
moves in PS on the 8 bit data.  That's fine to do, but doing full tonal
correction on 8 bit data is going to give you VERY VISIBLE posterization for
most images.

BTW, anyone is welcome to pass any of my remarks on as you see fit.

Also, I encourage anyone to do as I suggest above, and take a raw image from
your scanner, set the setpoints (NO tonal corrections) and convert it to 8
bits...then do your tonal corrections.  See how you like the results ;-)

Austin

I agree with Austin. If you have a good scan, you can make small adjustments
in 8-bit mode without problems. As you work with digital B&W, you will
eventually encounter images that are very delicate or you want a large
adjustment, and if adjusted in 8-bit mode they lose some of the tones
causing posterization or flat spots in the tone curve that are very
unappealing. This is often not visible on screen but shows up in the print.

One area that is very prone to this is the application of RGB separation
curves that are used with the MIS-VM and other ink sets. In order to force
the Epson driver to partition the inks where we want them the RGB curves are
often very radical. This can induce posterization in 8-bit mode at the final
step when everything is looking just fine on screen.

While it is possible to work around the 8-bit limit and make all of your
adjustments in 16-bit mode, it is not as easy as working in 8-bit. Dan's
remarks are unfortunate in that they will then to discourage Adobe from
giving us full editing features in 16-bit. Something I feel would be of
great benefit for B&W. With 16-bit editing we would all spend a lot less
time tweaking and struggling with the delicate tones in our prints.

Martin Wesley
http://www.borderless-photos.de/guests.html



----- Original Message -----
From: "Austin Franklin" <darkroom@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Tuesday, May 21, 2002 8:12 PM
Subject: RE: [Digital BW] 8x16 bits and BW


> > -Dan's answer:
> >
> > Technically there is more of a case for 16-bit in B/W than in
> > color images,
> > however it's unlikely to make any real difference.
>
> I find Dan's comments on this topic quite wrong.  Doing tonal moves in 8
> bit, CAN make a REAL difference.  It's a fact.
>
> Here's one of the rubs of this issue.  If you select 8 bit data from the
> scanner, the scanner driver typically does the tonal corrections TO high
bit
> data, then converts the high bit data to 8 bit data and sends you the
> corrected 8 bit data, so you don't have to do much tonal correcting in PS,
> if any, unless you want to "mess-up" your image.
>
> So, how do you get 8 bit data out of the scanner to do your tonal
> corrections to it in the first place?  On my scanner, I would have to scan
> in 16 bit raw, and once in PS, set the setpoints, and then convert it to 8
> bit data...the do tonal corrections to it.
>
> If you don't quite understand the implications of that, and why all that
> matters, let me know and I can explain further...
>
> > Bit depth works along the same lines, although it doesn't have nearly as
> > pronounced an effect as, resolution.
>
> That is not true, especially as a blanket statement.  It depends on the
> output image size for resolution.  Resolution change from 1k to 4k SPI may
> have no effect on a smaller print, but a huge effect on a larger print, as
> well as it's certainly film size dependant.
>
> Doing tonal changes in 8 bits can wipe out ranges of tones completely, or
> can have little effect...it is very image dependant, and it is also image
> size dependant.  I am assuming this discussion is limited to images of
> sufficient size (say a minimum of 8 x 8, 8 x 10 or larger) such that the
> image displays a large enough print area for you to see the full range of
> tonality from a decent viewing distance.
>
> > Similarly, less resolution provides a crisper, snappier look, if
> > that's what
> > you want, or a harsh and jagged look if it isn't.
>
> And it also means your image is less accurate...since there is dropped
> information in the reproduced image.  You lose detail, whether it's
"crisper
> and/or snappier" or not.  A line-art image is "crisper and/or snappier"
but
> contains no real detail.
>
> > One can vary resolution quite a bit without hurting anything
>
> Only on small images, that, again, is a very inaccurate blanket statement.
> Scanning at anything but the optical resolution of the scanner (except in
> the case of grain aliasing) WILL degrade the image.
>
> > Varying bit depth has a similar effect, but much less of it. That is,
> > pictures corrected in 8-bit will, if the correction was very aggressive,
> > seem
> > very slightly sharper than those done in 16-bit.
>
> Hum, that's again, not necessarily true.  It wouldn't necessarily seem
> sharper.  It depends on what, exactly, you do.  What happens when you do
> tonal corrections in an 8 bit space, is you ALWAYS lose tones, that is if
> the original image contained all 256 tones in the first place.  A lot of
> pixels that used to have different values, will now have the same value...
> An example is taking four pixels, values 100, 101, 102 and 103.
Performing
> a move on them so every pixel with the values 100-103 now all have the
value
> 103.  You just dropped three tones out of four...and if that happened over
> the entire tonal range, you'd have 64 tones, instead of 256.
>
> When you do tonal corrections, you are doing one of three things.  You are
> compressing a region, which loses tonal values as shown above, changing
the
> white and/or black endpoints (set points, and it's really a compression
> too), which also loses tonal values or you are expanding a region....which
> doesn't necessarily lose pixel values, the expansion has to compress some
> other region...
>
> If the lost tones are in a region of tonality (or a region of the image)
you
> don't care about, OR, especially more the case, are tones that there
aren't
> many pixels of that tonality, it won't have as drastic a visual effect.
It
> all depends on what quality of output you want, and where the dropped
tones
> lie.
>
> > ...In
> > B/W, this effect doesn't exist, so there would be a lot more
> > cases where one
> > might have a slight preference for a 16-bit correction.
>
> "slight preference"...well, it's far more than a "slight preference".  I
> think the issue is strongly masked by the fact that most people get their
> tonality set in the scanner driver, which, as I said above, does the tonal
> move on high bit data.  After getting the data in PS, they only do small
> moves in PS on the 8 bit data.  That's fine to do, but doing full tonal
> correction on 8 bit data is going to give you VERY VISIBLE posterization
for
> most images.
>
> BTW, anyone is welcome to pass any of my remarks on as you see fit.
>
> Also, I encourage anyone to do as I suggest above, and take a raw image
from
> your scanner, set the setpoints (NO tonal corrections) and convert it to 8
> bits...then do your tonal corrections.  See how you like the results ;-)
>
> Austin
>
>
>
> Please visit the Group Homepage to check the Files, Bookmarks, Polls and
other resources as they are often being updated. The page is at:
>
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
>
> Please follow these basic guidelines:
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> - Good manners are required at all time. No personal attacks or
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> - Before posting a question, search the message archives and the various
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>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

> Dan's
> remarks are unfortunate in that they will then to discourage Adobe from
> giving us full editing features in 16-bit. Something I feel would be of
> great benefit for B&W.

Hi Martin,

Yes, and I agree with you completely too.  It IS unfortunate, that, though
Dan does know a lot about color, his misinformation/misunderstandings with
respect to B&W will, unfortunately, be taken as correct by some people that
matter.  Sigh.

It doesn't matter if you're right or wrong any more, just that you've
written a book...  (sorry, I couldn't resist saying that ;-)

Regards,

Austin

on 5/21/02 11:12 PM, Austin Franklin wrote:

> I find Dan's comments on this topic quite wrong.  Doing tonal moves in 8
> bit, CAN make a REAL difference.  It's a fact.

Austin

Just keep one thing in mind, and as you don't monitor his list I don't
expect you to know this. This topic, specifically as it relates to Dan
Margulis, has been DISCUSSED to death. The whole slant that Dan brings to
the conversation is to drop the TALK of why bit depth matters and SHOW
IMAGES that support the logic.

So far, many people have DISCUSSED the logic of utilizing higher bit depths,
some of them highly regarded PS gurus who consult, write, teach, and do
major ad campaigns with PS. But none have presented IMAGES (as in photos) to
support their case.

Any of us who've looked seriously at the bit depth issue know why what Dan
says is (supposed to be?) wrong, but heretofore nobody has stepped up to the
plate to visually, with images, demonstrate him to be so - which IS his
challenge. He never issued a challenge to have the logic explained to him.
He began the challenge by explaining the logic behind highbit editing and
admitting he bought into it for many years for all the mathematical
reasons...BUT...all the while his eyes told him otherwise.

And to be fair, he never said working an image in 16-bit was a bad thing to
do, just that with the larger "freight" associated with doing so (file size,
memory requirements, etc) and more cumbersome workflow (lack of layers, etc)
he feels the people who advocate the higher workload owe it to their
listeners to demonstrate it's worth the added effort. I think that's valid,
don't you? Naturally, they feel otherwise. They feel they are generous
enough just bestowing their wisdom, which I can see too, and so the
"challenge" waits.

Now, on the other side of the equation, the criticism against Dan's
challenge is that the parameters of it have been less than excruciatingly
well defined, and some feel they may be a moving target - I don't know if he
includes grayscale images in it or not, for instance. But if you think
you're ready to step to the plate and put some images with your words - and
I don't mean diagrams, histograms, and equations - I mean posterized prints,
or what have you, I'll gladly forward his contact info to you so you can
discuss the details with him.

BTW, regarding Dan, while he is not afraid to take on the big wigs of the
industry in the most direct and confrontational manner, through this debate
I've had the pleasure to meet him (he lives nearby), and on a personal level
he is a really nice guy - warm, witty, personable, respectful, kind, etc. -
so don't be fooled by the nature of the "challenge". I don't believe he's
out to embarrass anybody, he simply wants to bust the hype (or make a little
of his own, I'm sure). It's not about the numbers to him, it's about ink on
paper, or pixels through monitor, or a file trough a film recorder, etc.
IOW, it's about how people PERCIEVE an image. The image, the image, the
image...

BTW 2, he's been known to be wrong before. I'm told (I haven't seen it) that
in an earlier edition of his book he made a major guffaw by utilizing the
same image at four different resolutions and proclaiming that when printed
at his books line screen no readers would be able to tell the difference
between them. Apparently the differences were obvious and he looked foolish.

Other times he's shown two different "corrections" of an image side by side
and proclaimed any fool would pick "version B" as the better version, only
to be swamped by reader mail saying they much preferred "version A". In the
case I'm thinking of the image was a white seal on snow. He liked the darker
image better because of how much more detail was present. I was among the
group that preferred the lighter version because I felt it was more
neutrally colored, and the lightness was more representative of my
perception of whites on a bright day. "More" detail was unnecessary.

So, go for it. Show him that your results back up the logic. It's
unbelievable nobody has yet. It's as though everyone is watching a trash can
fire blaze, thinking someone should throw water on it, but nobody does...

Todd

on 5/21/02 11:34 PM, Martin Wesley wrote:

> While it is possible to work around the 8-bit limit and make all of your
> adjustments in 16-bit mode, it is not as easy as working in 8-bit. Dan's
> remarks are unfortunate in that they will then to discourage Adobe from
> giving us full editing features in 16-bit. Something I feel would be of
> great benefit for B&W. With 16-bit editing we would all spend a lot less
> time tweaking and struggling with the delicate tones in our prints.

I fully agree with you that I'd love fully functional 16-bit editing. And
when that happens there'll be no funny little debates, and Dan's challenge
will be a quaint reminder of our current technological immaturity.

But Russell Williams, who is a PS developer, has spoken plainly about this
on more than one list, and well before Dan Margulis spoke to the issue. His
apology is that the PS development team has limited manpower and man-hours,
and highbit editing is pretty low on their priority list compared to more
mundane enhancements like spell checkers, type effects, web effects, neat
filters, OS support, and the like.

Sadly, fine art photographers, or whoever of us who desire the utmost in
image quality, are a niche market for Adobe, compared to everyday web and
print designers.

But so too is the case for us as BW printers, in a color printer's world.
So, much as Epson now incrementally includes BW capabilities in their
printers, so too does Adobe include 16-bit editing in their program - bit by
stinking bit (hideously tacky pun intended ;-)

Todd

Unlike Photoshop, all of the Picture Window Pro transformations and editing
features work in both 8 and 16 bit, PWP can read and use the Photoshop
curves used for black and white printing, and it's cheaper than many
Photoshop plug-ins (about $100). www.dl-c.com.

I frequently edit in PWP and 16 bits, then save the TIFF file and open it in
Photoshop if I need to do things to the file that PWP won't do and Photoshop
will.

- David

-----Original Message-----
From: Todd Flashner [mailto:tflash@...]
Sent: Wednesday, May 22, 2002 1:09 AM
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: Re: [Digital BW] 8x16 bits and BW


on 5/21/02 11:34 PM, Martin Wesley wrote:

> While it is possible to work around the 8-bit limit and make all of your
> adjustments in 16-bit mode, it is not as easy as working in 8-bit. Dan's
> remarks are unfortunate in that they will then to discourage Adobe from
> giving us full editing features in 16-bit. Something I feel would be of
> great benefit for B&W. With 16-bit editing we would all spend a lot less
> time tweaking and struggling with the delicate tones in our prints.

I fully agree with you that I'd love fully functional 16-bit editing. And
when that happens there'll be no funny little debates, and Dan's challenge
will be a quaint reminder of our current technological immaturity.

But Russell Williams, who is a PS developer, has spoken plainly about this
on more than one list, and well before Dan Margulis spoke to the issue. His
apology is that the PS development team has limited manpower and man-hours,
and highbit editing is pretty low on their priority list compared to more
mundane enhancements like spell checkers, type effects, web effects, neat
filters, OS support, and the like.

Sadly, fine art photographers, or whoever of us who desire the utmost in
image quality, are a niche market for Adobe, compared to everyday web and
print designers.

But so too is the case for us as BW printers, in a color printer's world.
So, much as Epson now incrementally includes BW capabilities in their
printers, so too does Adobe include 16-bit editing in their program - bit by
stinking bit (hideously tacky pun intended ;-)

Todd



Please visit the Group Homepage to check the Files, Bookmarks, Polls and
other resources as they are often being updated. The page is at:

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Please follow these basic guidelines:
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"flames."
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Austin,

I know you've said this before, and I'm sure we may have discussed it before
(if so, I forgot!) but do you have examples of which scanners might do it
like this? (tonal corrections in high-bit data, then convert to low-bit
data)

I did do some tests on this - can't remember now if it was with the Nikon
Coolscan 3 or the 4000, but I found that (whilst Nikon claim they do tonal
corrections in high-bit) doing any kind of end-point adjustment resulted in
substantial combing in the histogram. I think it was during that process
that i also found out that NikonScan's histogram display was also
exceedingly unreliable - displaying 'substantially' different data even
after a full scan and save ... compared to after reopening the scan file.
(in other words both at times when one would expect the software to be able
to correctly count ALL pixel values... rather than speculation based on a
preview scan.

My sense tells me that scanners should be set up something like this:
Light source -> Film -> Sensor -> 'x'bit ADC -> Data 'tonal' adjustment ->
Convert to output bit depth -> out to computer

Where 'data tonal adjustment' would be using some kind of Look-Up-Table or
function to convert incoming raw data to corrected value... and 'Convert to
output bit depth' which converts high bit data to 8 bit if appropriate.
There must also be some additional steps I would guess, to combine colour
data etc for a mono scan (not in the Leaf case, I know!!!), but I am looking
for the essentials!

Would that be about right on flow? And if so, what would your estimation be
on what Nikon might have done that could result in combing on tonal
adjustments?

I should add that I haven't tested this in a while (so perhaps later version
of NikonScan resolved things), but I do not believe that I was mistaken when
I did my tests ;)

Nij



> -----Original Message-----
> From: Austin Franklin [mailto:darkroom@...]
<snip>
> Here's one of the rubs of this issue.  If you select 8 bit data from the
> scanner, the scanner driver typically does the tonal corrections
> TO high bit
> data, then converts the high bit data to 8 bit data and sends you the
> corrected 8 bit data, so you don't have to do much tonal correcting in PS,
> if any, unless you want to "mess-up" your image.
<snip>

Hi Todd,

> ...and Dan's challenge

I believe Dan's "challenge" is specifically for COLOR, not B&W.

Austin

> The whole slant that Dan brings to
> the conversation is to drop the TALK of why bit depth matters and SHOW
> IMAGES that support the logic.

Hi Todd,

Well, most ALL have done B&W images that posterize...and that disproves his
claim.

> So far, many people have DISCUSSED the logic of utilizing higher
> bit depths,
> some of them highly regarded PS gurus who consult, write, teach, and do
> major ad campaigns with PS. But none have presented IMAGES (as in
> photos) to
> support their case.

But, they are specifically talking about color, and for color, what Dan says
(as well as others, including my self) is correct, but that is only for
color.  With 8 bit color you have 24 bits, not 8.  With grayscale you have 8
bits, and that's it.  It's an entirely different matter.

> ...heretofore nobody has
> stepped up to the
> plate to visually, with images, demonstrate him to be so - which IS his
> challenge.

Read what he was just quoted as saying here...he ONLY mentions color in his
claim...

> he feels the people who advocate the higher workload owe it to their
> listeners to demonstrate it's worth the added effort.

Where do you believe posterizing comes from, if you have a good original
scan?  The posterizing issue has been discussed many times...and most always
the solution is...to do tonal correction in 16 bits, and that solves the
posterizing.  I don't get any posterizing any more, since I learned TO do my
tonal corrections in the scanner, and not in PS, which as I've said, the
scanner does do tonal correction in high bit, and gives PS an 8 bit
file...and when I try to correct the 8 bit file in PS, I sometimes get
posterizing.  That's entirely demonstrable.  Be aware that you may not see
posterizing on the screen, but you will in the histogram and then in the
actual print.

> ...and so the
> "challenge" waits.

Well, no it doesn't...not for B&W.  As Dan if his "challenge" is for B&W, if
it is, I will gladly put my money where my mouth is.

> Now, on the other side of the equation, the criticism against Dan's
> challenge is that the parameters of it have been less than excruciatingly
> well defined, and some feel they may be a moving target - I don't
> know if he
> includes grayscale images in it or not, for instance.

I assure you he does not include grayscale...NOW...but when he first made
these claims, he was only thinking in terms of color, not B&W...and now he
qualifies everything with "color".

> But if you think
> you're ready to step to the plate and put some images with your
> words - and
> I don't mean diagrams, histograms, and equations - I mean
> posterized prints,

Any time.

> I'll gladly forward his contact info to you so you can
> discuss the details with him.

Well, I don't want to discuss anything with him, I'd like to see his claim
in writing, in public.

> ...and on a
> personal level
> he is a really nice guy - warm, witty, personable, respectful,
> kind, etc. -
> so don't be fooled by the nature of the "challenge". I don't believe he's
> out to embarrass anybody, he simply wants to bust the hype (or
> make a little
> of his own, I'm sure).

But this is what's got my questioning his "honesty".  Showing posterization
in B&W is very common, and very easy to do.  If he had a clue, then why not
just do it for himself.  If I remember right, didn't YOU do some images to
see for your self?  Did you scan as I suggested, in RAW mode, and set the
setpoints then convert to 8 bits and do the tonal adjustments?  If not, do
it and see for your self, as you live near him, and can bring him the
prints!

> So, go for it. Show him that your results back up the logic. It's
> unbelievable nobody has yet.

It is, IF he is also talking about grayscale, which I am most positive he
will back away from.  Please, ask him.

Austin

Austin

You may well be right that Dan excludes BW from his challenge, in which case
I apologize. I'm checking into it, I'll let you know.

For the record, I don't disagree with you either, I just get frustrated that
so many people have stated the case for color as forcefully as you have for
BW but never show their goods. Unfortunately I've followed this thread on
too many disparate lists and bring my frustrations with me where I go, which
isn't always fair the the poster at hand.

Todd

>> The whole slant that Dan brings to
>> the conversation is to drop the TALK of why bit depth matters and SHOW
>> IMAGES that support the logic.
> 
> Hi Todd,
> 
> Well, most ALL have done B&W images that posterize...and that disproves his
> claim.
> 
>> So far, many people have DISCUSSED the logic of utilizing higher
>> bit depths,
>> some of them highly regarded PS gurus who consult, write, teach, and do
>> major ad campaigns with PS. But none have presented IMAGES (as in
>> photos) to
>> support their case.
> 
> But, they are specifically talking about color, and for color, what Dan says
> (as well as others, including my self) is correct, but that is only for
> color.  With 8 bit color you have 24 bits, not 8.  With grayscale you have 8
> bits, and that's it.  It's an entirely different matter.
> 
>> ...heretofore nobody has
>> stepped up to the
>> plate to visually, with images, demonstrate him to be so - which IS his
>> challenge.
> 
> Read what he was just quoted as saying here...he ONLY mentions color in his
> claim...
> 
>> he feels the people who advocate the higher workload owe it to their
>> listeners to demonstrate it's worth the added effort.
> 
> Where do you believe posterizing comes from, if you have a good original
> scan?  The posterizing issue has been discussed many times...and most always
> the solution is...to do tonal correction in 16 bits, and that solves the
> posterizing.  I don't get any posterizing any more, since I learned TO do my
> tonal corrections in the scanner, and not in PS, which as I've said, the
> scanner does do tonal correction in high bit, and gives PS an 8 bit
> file...and when I try to correct the 8 bit file in PS, I sometimes get
> posterizing.  That's entirely demonstrable.  Be aware that you may not see
> posterizing on the screen, but you will in the histogram and then in the
> actual print.
> 
>> ...and so the
>> "challenge" waits.
> 
> Well, no it doesn't...not for B&W.  As Dan if his "challenge" is for B&W, if
> it is, I will gladly put my money where my mouth is.
> 
>> Now, on the other side of the equation, the criticism against Dan's
>> challenge is that the parameters of it have been less than excruciatingly
>> well defined, and some feel they may be a moving target - I don't
>> know if he
>> includes grayscale images in it or not, for instance.
> 
> I assure you he does not include grayscale...NOW...but when he first made
> these claims, he was only thinking in terms of color, not B&W...and now he
> qualifies everything with "color".
> 
>> But if you think
>> you're ready to step to the plate and put some images with your
>> words - and
>> I don't mean diagrams, histograms, and equations - I mean
>> posterized prints,
> 
> Any time.
> 
>> I'll gladly forward his contact info to you so you can
>> discuss the details with him.
> 
> Well, I don't want to discuss anything with him, I'd like to see his claim
> in writing, in public.
> 
>> ...and on a
>> personal level
>> he is a really nice guy - warm, witty, personable, respectful,
>> kind, etc. -
>> so don't be fooled by the nature of the "challenge". I don't believe he's
>> out to embarrass anybody, he simply wants to bust the hype (or
>> make a little
>> of his own, I'm sure).
> 
> But this is what's got my questioning his "honesty".  Showing posterization
> in B&W is very common, and very easy to do.  If he had a clue, then why not
> just do it for himself.  If I remember right, didn't YOU do some images to
> see for your self?  Did you scan as I suggested, in RAW mode, and set the
> setpoints then convert to 8 bits and do the tonal adjustments?  If not, do
> it and see for your self, as you live near him, and can bring him the
> prints!
> 
>> So, go for it. Show him that your results back up the logic. It's
>> unbelievable nobody has yet.
> 
> It is, IF he is also talking about grayscale, which I am most positive he
> will back away from.  Please, ask him.
> 
> Austin

on 5/22/02 9:41 AM, Austin Franklin wrote:

> But, they are specifically talking about color, and for color, what Dan says
> (as well as others, including my self) is correct, but that is only for
> color.  With 8 bit color you have 24 bits, not 8.  With grayscale you have 8
> bits, and that's it.  It's an entirely different matter.


Okay Austin, It seems you are correct. Below was part of Dan's recent post,
and as you said, he does indeed specify "color":

"I therefore issued a challenge for those who could come up with any color
photographic image where any reasonable course of events might conceivably
show an advantage for working in 16-bit as opposed to just converting
immediately to 8-bit, and said if I could verify it I would admit it and
print the results."

But how 'bout showing us some of your posterized images for our edification?
It's most interesting when the same moves are made to a duplicate 8-bit and
16-bit file and the two are compared. If you remember my little article on
the topic 
(<http://www.ourwebmaster.com/piezography3000/20020106ToddFlashner1.htm>),
which did use a BW image, fairly substantial moves can be made before
deterioration shows. Remember, we only need to retain a max of about 100
tones for a BW print; which means we can lose 156 out of 256. That's a lot
of admissible loss. The other thing is, even IF the 16-bit image looks
different than the 8-bit, does it look better?

I believe if/when this debate actually includes images the understanding of
the perceptual forces at work will be very interesting, which is why I'm
such a prod to get people to participate. It's not just if tones get lost,
it's how many, and where in the image, and what type of image.

Todd

Hi Todd,

> But how 'bout showing us some of your posterized images for our
> edification?

Well, that is a problem.  You need to see prints, not web images...  Images
can look fine on the screen, but when you print them, they are posterized.

> It's most interesting when the same moves are made to a duplicate
> 8-bit and
> 16-bit file and the two are compared. If you remember my little article on
> the topic
> (<http://www.ourwebmaster.com/piezography3000/20020106ToddFlashner1.htm>),
> which did use a BW image, fairly substantial moves can be made before
> deterioration shows.

But that is VERY image dependant...

> Remember, we only need to retain a max of about 100
> tones for a BW print; which means we can lose 156 out of 256.

Actually, no.  It depends on WHAT tones you "lose" and where they are.

> It's not just if tones get lost,
> it's how many, and where in the image, and what type of image.

Exactly!

Austin

Hey Austin

You and I are in great agreement over everything but one. I believe such
discussions are MOST informative when people demonstrate what they are
speaking of. The only reason I kinda take Dan's side in this whole thing is
because all he's asking for is a presentation of evidence so that he can eat
his hat. I'd like to see the evidence too, not to see Dan eat his hat, but
to get into the whole "image dependant" thing. Everybody wants to say it's
image dependant, but nobody seems to give a hoot about what types of images
those are!

>> But how 'bout showing us some of your posterized images for our
>> edification?
> 
> Well, that is a problem.  You need to see prints, not web images...  Images
> can look fine on the screen, but when you print them, they are posterized.

So scan the prints.

>> It's most interesting when the same moves are made to a duplicate
>> 8-bit and
>> 16-bit file and the two are compared. If you remember my little article on
>> the topic
>> (<http://www.ourwebmaster.com/piezography3000/20020106ToddFlashner1.htm>),
>> which did use a BW image, fairly substantial moves can be made before
>> deterioration shows.
> 
> But that is VERY image dependant...

We both know it's all image dependent, but if nobody shows what types of
images handle abuse well and what types don't, we don't know what to make of
that knowledge... Other than walking on eggshells. And I believe that was
the point f Dan's challenge. The current conventional wisdom is that we all
need to walk on eggshells while doing any 8-bit manipulations, when in
reality some 99% of images do get 8-bit manipulations and do quite well by
them.

The other point is, if it's so damn difficult to demonstrate how the images
fail, the failure can't be as common or critical as we are led to believe.
 
>> Remember, we only need to retain a max of about 100
>> tones for a BW print; which means we can lose 156 out of 256.
> 
> Actually, no.  It depends on WHAT tones you "lose" and where they are.

Indeed. But think about it, some people get squirrelly if they see ANY gaps
in their histogram, when theoretically they only need to retain some 40% of
the tones, IF they are appropriately distributed.

I'm only trying to give people some freedom here. I bet at least 80% of the
people on this list do almost all their PS manipulations on 8-bit files, and
some minute percentage of those people get posterization in their prints
that ARE the result of inadequate bit depth. I bet of the percentage of
people who work their images exclusively in 16-bit have ALSO had a minute
occurrence of posterized prints. (see below)

>> It's not just if tones get lost,
>> it's how many, and where in the image, and what type of image.
> 
> Exactly!

The problem with most peoples experience in this matter is that one day they
work an image in 8-bits and they get a bad print. Another day they work a
different image in 16-bits and get a good print. They conclude working all
images in 16-bits is the fix. If they were to do side by side manipulations
to the same file, one in 8-bits and one in 16, they might just find the
16-bit file prints the same as the 8-bit.

I know I'm redundant in this, but not all image failures that are attributed
to inadequate bit depth are in fact that. Some of my scans, when I
manipulate them in a certain way, get harsh transitions between tones that
might appear to be posterization, BUT it happens the same in the 16-bit
variant. It is only through side by side comparisons that that phenomenon
reveals itself to be something other than "lost" tones.

Todd

> >> But how 'bout showing us some of your posterized images for our
> >> edification?
> >
> > Well, that is a problem.  You need to see prints, not web
> images...  Images
> > can look fine on the screen, but when you print them, they are
> posterized.
>
> So scan the prints.

Well, that really doesn't work either...  Seeing the prints does, so why
waste your time futzing around with anything else?  I guess I don't
understand what the problem is.  Are you saying you have NEVER had visible
posterization by making tonal corrections to your 8 bit files?

> We both know it's all image dependent, but if nobody shows what types of
> images handle abuse well and what types don't, we don't know what
> to make of
> that knowledge...

I don't know that it can be characterized...and if it can, that may take a
bit of work.  I KNOW that I used to get posterization doing tonal
corrections to 8 bit files, so now I just make sure I get my tonal
corrections done in the scanner driver, and voila!  No posterization at all
in any of my prints.  Why can't Dan (or you) just do this your self?

> The current conventional wisdom is
> that we all
> need to walk on eggshells while doing any 8-bit manipulations, when in
> reality some 99% of images do get 8-bit manipulations and do quite well by
> them.

Not at all.  It depends on WHAT you are doing, and what your images look
like, and how your scanner is set-up etc., what scanner you are using...bla
bla bla.  There are so many variables that to try to quantify this with some
exact number is a fool's errand.  I KNOW that it's far more than %1 from my
personal experience, and if I had to guess, it would be more like %75...and
I am talking about INITIAL tonal correction to a raw 8 bit file, file
derived as I've specified previously.  Now, if you are talking about just
small moves on a file that has all tones present...then it will be much much
less, of course.

> The other point is, if it's so damn difficult to demonstrate how
> the images
> fail, the failure can't be as common or critical as we are led to believe.

Well, I know I can see it in a heartbeat with my images!

> >> Remember, we only need to retain a max of about 100
> >> tones for a BW print; which means we can lose 156 out of 256.
> >
> > Actually, no.  It depends on WHAT tones you "lose" and where they are.
>
> Indeed. But think about it, some people get squirrelly if they
> see ANY gaps
> in their histogram,

And there's nothing wrong with that.  Assuring you have a full tonal range
will assure you of no posterization in most every image.  Easy, why fuss
with it?

> I'm only trying to give people some freedom here. I bet at least
> 80% of the
> people on this list do almost all their PS manipulations on 8-bit
> files,

See, that's where I think this whole subject is misleading.  Most people
don't do their initial tonal corrections on 8 bit files intentionally.
Again, the initial tonal correction is done in the scanner driver...so if
you're doing some minor correction on an 8 bit file in PS, it stands a much
higher chance of being insignificant.

> The problem with most peoples experience in this matter is that
> one day they
> work an image in 8-bits and they get a bad print. Another day they work a
> different image in 16-bits and get a good print. They conclude working all
> images in 16-bits is the fix.

How do you know that is what they did?  I doubt that.

Austin

To all who think 8 bit color correcting is identical to 16. Just try it
yourself with one of your own images. One scanned in 16 bit, and one in
8. Make identical adjustments.

If you can't see any difference, there is something VERY weird going on...

Jerry




Austin Franklin wrote:

> 
> > Dan's
> > remarks are unfortunate in that they will then to discourage Adobe from
> > giving us full editing features in 16-bit. Something I feel would be of
> > great benefit for B&W.
> 
> Hi Martin,
> 
> Yes, and I agree with you completely too.  It IS unfortunate, that, though
> Dan does know a lot about color, his misinformation/misunderstandings with
> respect to B&W will, unfortunately, be taken as correct by some people that
> matter.  Sigh.
> 
> It doesn't matter if you're right or wrong any more, just that you've
> written a book...  (sorry, I couldn't resist saying that ;-)
> 
> Regards,
> 
> Austin
> 
> 
> Please visit the Group Homepage to check the Files, Bookmarks, Polls and other resources as they are often being updated. The page is at:
> 
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
> 
> Please follow these basic guidelines:
> - Include your full name with your message.
> - Include the address of your website, if you have one.
> - As threads develop, trim off excess portions of earlier messages to keep them short.
> - As the topic of a thread changes remember to change the subject header.
> - Good manners are required at all time. No personal attacks or "flames."
> - Complete your Yahoo profile.
> - Before posting a question, search the message archives and the various resources on the homepage.
> 
> 
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

Whatever Austin.

You keep saying how easily your images can posterize and if Dan want's to
see it, or for lunch at Le Cirque, no problemo, you have images ready to
show. However, whenever I ask to see them you waffle.

You also keep talking to me like I don't understand the topic, or know how
to avoid posterization in my own images; as if I'm having a problem I'm
asking you to solve. I think you know I scan and manipulate in 16-bit
routinely and have a decent knowledge of the subject and how to utilize my
scanner, Photoshop, and my printer. I hope that doesn't sound arrogant, I'm
not saying I'm good, just that you know I'm more competent than the person
your comments seem to be addressing.

All I was asking you to do was to demonstrate your results - the same
results you say you can obtain and recognize in a heartbeat. I was trying to
advance he discussion for the benefit of others, but I see that ain't going
to happen here.

Catch ya next time.

Todd

> 
>>>> But how 'bout showing us some of your posterized images for our
>>>> edification?
>>> 
>>> Well, that is a problem.  You need to see prints, not web
>> images...  Images
>>> can look fine on the screen, but when you print them, they are
>> posterized.
>> 
>> So scan the prints.
> 
> Well, that really doesn't work either...  Seeing the prints does, so why
> waste your time futzing around with anything else?  I guess I don't
> understand what the problem is.  Are you saying you have NEVER had visible
> posterization by making tonal corrections to your 8 bit files?
> 
>> We both know it's all image dependent, but if nobody shows what types of
>> images handle abuse well and what types don't, we don't know what
>> to make of
>> that knowledge...
> 
> I don't know that it can be characterized...and if it can, that may take a
> bit of work.  I KNOW that I used to get posterization doing tonal
> corrections to 8 bit files, so now I just make sure I get my tonal
> corrections done in the scanner driver, and voila!  No posterization at all
> in any of my prints.  Why can't Dan (or you) just do this your self?
> 
>> The current conventional wisdom is
>> that we all
>> need to walk on eggshells while doing any 8-bit manipulations, when in
>> reality some 99% of images do get 8-bit manipulations and do quite well by
>> them.
> 
> Not at all.  It depends on WHAT you are doing, and what your images look
> like, and how your scanner is set-up etc., what scanner you are using...bla
> bla bla.  There are so many variables that to try to quantify this with some
> exact number is a fool's errand.  I KNOW that it's far more than %1 from my
> personal experience, and if I had to guess, it would be more like %75...and
> I am talking about INITIAL tonal correction to a raw 8 bit file, file
> derived as I've specified previously.  Now, if you are talking about just
> small moves on a file that has all tones present...then it will be much much
> less, of course.
> 
>> The other point is, if it's so damn difficult to demonstrate how
>> the images
>> fail, the failure can't be as common or critical as we are led to believe.
> 
> Well, I know I can see it in a heartbeat with my images!
> 
>>>> Remember, we only need to retain a max of about 100
>>>> tones for a BW print; which means we can lose 156 out of 256.
>>> 
>>> Actually, no.  It depends on WHAT tones you "lose" and where they are.
>> 
>> Indeed. But think about it, some people get squirrelly if they
>> see ANY gaps
>> in their histogram,
> 
> And there's nothing wrong with that.  Assuring you have a full tonal range
> will assure you of no posterization in most every image.  Easy, why fuss
> with it?
> 
>> I'm only trying to give people some freedom here. I bet at least
>> 80% of the
>> people on this list do almost all their PS manipulations on 8-bit
>> files,
> 
> See, that's where I think this whole subject is misleading.  Most people
> don't do their initial tonal corrections on 8 bit files intentionally.
> Again, the initial tonal correction is done in the scanner driver...so if
> you're doing some minor correction on an 8 bit file in PS, it stands a much
> higher chance of being insignificant.
> 
>> The problem with most peoples experience in this matter is that
>> one day they
>> work an image in 8-bits and they get a bad print. Another day they work a
>> different image in 16-bits and get a good print. They conclude working all
>> images in 16-bits is the fix.
> 
> How do you know that is what they did?  I doubt that.
> 
> Austin
> 
> 
> 
> Please visit the Group Homepage to check the Files, Bookmarks, Polls and other
> resources as they are often being updated. The page is at:
> 
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
> 
> Please follow these basic guidelines:
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> - Include the address of your website, if you have one.
> - As threads develop, trim off excess portions of earlier messages to keep
> them short.
> - As the topic of a thread changes remember to change the subject header.
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> 
> 
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> 
>

Austin

Sorry I lost my cool. As I said I brought pre-existing frustration to the
conversation. Please don't take it personally!

Todd

Jerry,
 
I'm one of those you address, but my usual workflow is not what you suggest:
I *do* scan in 16 bits, actually I start with a raw scan from Vuescan. But
afterwards, I convert to 8bits in PS and tweak happily away.
Well, almost. Not being a fundamentalist, what I really do is open the raw
scan, apply levels to set black and white point, and only after this first
operation convert to 8 bits and start layering like crazy.
Anyway, when I made a few tests applying the same curves/levels/whatever to
the original 16bit and a 8bit copy of some images (always starting from a
16bit scan, though), I was rigorous, and I saw no difference *on screen*.
Now Austin makes me think I should redo these tests and print the two
images, although they look the same on my monitor... Just out of curiosity,
what do you think is the reason behind posterization showing up only on the
print? The further curves you apply with partitioning workflows or some
inherent difference between how monitors and printers render the image data?
 
Thanks,
Alessandro Pardi

-----Original Message-----
From: Jerry Olson [mailto:jerryolson@...]
Sent: giovedì 23 maggio 2002 05.23
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: Re: [Digital BW] 8x16 bits and BW


To all who think 8 bit color correcting is identical to 16. Just try it
yourself with one of your own images. One scanned in 16 bit, and one in
8. Make identical adjustments.

If you can't see any difference, there is something VERY weird going on...

Jerry




Austin Franklin wrote:
> 
> > Dan's
> > remarks are unfortunate in that they will then to discourage Adobe from
> > giving us full editing features in 16-bit. Something I feel would be of
> > great benefit for B&W.
> 
> Hi Martin,
> 
> Yes, and I agree with you completely too.  It IS unfortunate, that, though
> Dan does know a lot about color, his misinformation/misunderstandings with
> respect to B&W will, unfortunately, be taken as correct by some people
that
> matter.  Sigh.
> 
> It doesn't matter if you're right or wrong any more, just that you've
> written a book...  (sorry, I couldn't resist saying that ;-)
> 
> Regards,
> 
> Austin
> 
> 
> Please visit the Group Homepage to check the Files, Bookmarks, Polls and
other resources as they are often being updated. The page is at:
> 
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
<http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint> 
> 
> Please follow these basic guidelines:
> - Include your full name with your message.
> - Include the address of your website, if you have one.
> - As threads develop, trim off excess portions of earlier messages to keep
them short.
> - As the topic of a thread changes remember to change the subject header.
> - Good manners are required at all time. No personal attacks or
"flames."
> - Complete your Yahoo profile.
> - Before posting a question, search the message archives and the various
resources on the homepage.
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> 
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[Non-text portions of this message have been removed]

Hi Todd,

> You keep saying how easily your images can posterize and if Dan want's to
> see it, or for lunch at Le Cirque, no problemo, you have images ready to
> show. However, whenever I ask to see them you waffle.

Not waffling at all!  Why should I spend my time proving something to
someone who can easily, with a little work on their own, do the experiment
for them selves?

> You also keep talking to me like I don't understand the topic, or know how
> to avoid posterization in my own images; as if I'm having a problem I'm
> asking you to solve.

No, not at all.  I know you understand this, and as far as I know, you don't
have any problems with posterization.  Others read this discussion, and they
may not fully understand what you understand.

> I think you know I scan and manipulate in 16-bit
> routinely and have a decent knowledge of the subject and how to utilize my
> scanner, Photoshop, and my printer. I hope that doesn't sound
> arrogant, I'm
> not saying I'm good,

I have seen your prints, and I would say you are good, in fact, quite good.

> All I was asking you to do was to demonstrate your results - the same
> results you say you can obtain and recognize in a heartbeat.

But isn't it better for you (or others) to do it on your own, and see for
your self?

You can lead a horse to water... ;-)

Regards,

Austin

Hi Nij,

> Austin,
>
> I know you've said this before, and I'm sure we may have
> discussed it before
> (if so, I forgot!) but do you have examples of which scanners might do it
> like this? (tonal corrections in high-bit data, then convert to low-bit
> data)

I would say any scanner *SHOULD* do this...  I know my Leafscan 45 and 35 do
this.  The requirement is that the scanner have LUTs (Look Up Tables) in the
scanner, that the data passes through...and are loaded via the scanner
application with the tonal curve data you provide via a curves interface.

Basically, you need one LUT per color, and a LUT is nothing but a memory.
For a 16 bit scanner, it would be a 16 bit in and 16 bit out memory, or 128k
bytes of memory organized in 64k (16 address bits) x 16 bits per color.

> My sense tells me that scanners should be set up something like this:
> Light source -> Film -> Sensor -> 'x'bit ADC -> Data 'tonal' adjustment ->
> Convert to output bit depth -> out to computer

Correct.  Only one thing you missed, and that is either analog setpoints.
They typically happen after tonal adjustments, as data is toned in 16 bits,
so you have to wait until after the "move" to clip the setpoints.  The
setpoints can be done at the same time as the convert to 8 bit output BTW,
and the "range" of data that has the setpoints as the outer bounds is them
"mapped" into the 8 bit space.

> There must also be some additional steps I would guess, to combine colour
> data etc for a mono scan (not in the Leaf case, I know!!!),

Correct.  I've always wanted to see this mix be programmable in the scanner
driver...

> Would that be about right on flow?

Yes.

> And if so, what would your
> estimation be
> on what Nikon might have done that could result in combing on tonal
> adjustments?

Could be just bad software, or that it uses the preview for the histogram,
and the preview really is insufficient...

Regards,

Austin

As long as your operations are linear and you have maximal dynamic range 
there will be no difference between processing in 8 bits and processing 
in 16 bits and converting to 8.  That's pretty much covered in any 
textbook on signal processing, be it images (optical, IR or radar) or 
auido.

However, when you perform an significant nonlinear process or a series 
of nonlinear processes this may not be true. Applying curves - 
expecially "radical curves"  is a nonlinear process since it expands and 
dialates the range based on value. On images with long toes and/or 
shoulders this could be an issue. I could see where this type of 
processing would cause posterization on 8 bit images but not on 16 bit 
images.

Monitors are a pretty poor display device so it's not surprising it 
doesn't show up there. Prints are also viewed using reflected light and 
monitors are viewed using transmitted light. That probably also makes a 
difference.

Truman

Alessandro Pardi wrote:

> Jerry,
>
> I'm one of those you address, but my usual workflow is not what you 
> suggest:
> I *do* scan in 16 bits, actually I start with a raw scan from Vuescan. But
> afterwards, I convert to 8bits in PS and tweak happily away.
> Well, almost. Not being a fundamentalist, what I really do is open the raw
> scan, apply levels to set black and white point, and only after this first
> operation convert to 8 bits and start layering like crazy.
> Anyway, when I made a few tests applying the same 
> curves/levels/whatever to
> the original 16bit and a 8bit copy of some images (always starting from a
> 16bit scan, though), I was rigorous, and I saw no difference *on screen*.
> Now Austin makes me think I should redo these tests and print the two
> images, although they look the same on my monitor... Just out of 
> curiosity,
> what do you think is the reason behind posterization showing up only 
> on the
> print? The further curves you apply with partitioning workflows or some
> inherent difference between how monitors and printers render the image 
> data?
>
> Thanks,
> Alessandro Pardi

Hi Allessandro,

Well on my images the noise in the shadows on the monitor is very
obvious when I scan a slide in 8 bits. If you make a large tone
adjustment in an 8 bit scan and then scan the same slide in 16 bits and
make the same adjustment, its obivous on my monitor that the 8 bit scan
is inferior. I don't have to make a print to prove it. Its almost always
that noise shows up in the shadows. Also splotches, or mottle. This
doesn't happen in 16 bit.

 I realize this is image dependent, and wouldn't show up in all images.
It doesn't show up in ALL my images, and never in digital camera images.
I usually shoot the digital camera images in raw, make any curve
adjustments and then save it in 8 bits.  There isn't a posterization
problem at all with my Canon D30. In fact, I don't think I've ever seen
posterization in any image taken with the camera. Shadow detail with a
digital camera seems a lot better than with film, so It might not even
need the 16 bit raw image to begin with, but I do it anyway, just to be safe.

It's much worse in scanning a black and white negative, and if I'm going
to make a large tonal adjustment, I MUST scan the negative in 16 bit.  

If you just scan and print and don't make any curve or level adjustments
at all, then it isn't nearly as bad, and in small prints, probably
wouldn't even show up.  A lot of images probably don't need a lot of
tonal adjustments. But I have this one particular client who insists on
using slow, contrasty films like velvia. And you have to make a real
effort to get acceptable (Not great, just acceptable) shadow detail,
requiring a very large curve adjustment. I just couldn't do it in 8 bit. 

I hope this discussion will result in people actually trying this for
themselves, and see the results on their own screens. If nobody can see
the difference, on their monitors, I must be doing something very
wrong!! I could have some setting wrong and that could be the cause. 

> I was rigorous, and I saw no difference *on screen*.

Maybe your scans are so good that you don't have the problem. I would
imagine a drum scan wouldn't have nearly the problems that ordinary
desktop filmscanners have.

Just out of curiosity,
> what do you think is the reason behind posterization showing up only on the
> print? 

For me, I can see the difference on the monitor. It looks like mottled,
spotchy patches.

Jerry

Austin

 Why do you keep suggesting I conduct tests you know I've conducted many
times over. You don't want to show your results, fine, just admit it, but
please stop telling me to do what you know I've done. I've done the tests
for myself, I've done them for Dan, and I've twice made the scans he's used
for his tests.

As for others, not everybody does have the capability to conduct these
tests, and all they hear is "it's image dependant", or from you that your
images posterize EASILY. My article demonstrated that many of my images can
take robust manipulations without detriment, and I, and perhaps others,
might be interested to know why your images are more vulnerable to it than
mine. It could help to explain WHY there is debate at all on the subject,
and why it is not as cut and dry as some might have them believe. I though
"show and tell" might be more illustrative than tell and tell and tell and
tell.

Now, if you don't care enough to put the energy into it I FULLY understand
that, but please stop making it seems like it's other peoples unwillingness.

Todd

> Hi Todd,
> 
>> You keep saying how easily your images can posterize and if Dan want's to
>> see it, or for lunch at Le Cirque, no problemo, you have images ready to
>> show. However, whenever I ask to see them you waffle.
> 
> Not waffling at all!  Why should I spend my time proving something to
> someone who can easily, with a little work on their own, do the experiment
> for them selves?
> 
>> You also keep talking to me like I don't understand the topic, or know how
>> to avoid posterization in my own images; as if I'm having a problem I'm
>> asking you to solve.
> 
> No, not at all.  I know you understand this, and as far as I know, you don't
> have any problems with posterization.  Others read this discussion, and they
> may not fully understand what you understand.
> 
>> I think you know I scan and manipulate in 16-bit
>> routinely and have a decent knowledge of the subject and how to utilize my
>> scanner, Photoshop, and my printer. I hope that doesn't sound
>> arrogant, I'm
>> not saying I'm good,
> 
> I have seen your prints, and I would say you are good, in fact, quite good.
> 
>> All I was asking you to do was to demonstrate your results - the same
>> results you say you can obtain and recognize in a heartbeat.
> 
> But isn't it better for you (or others) to do it on your own, and see for
> your self?
> 
> You can lead a horse to water... ;-)
> 
> Regards,
> 
> Austin
> 
> 
> 
> Please visit the Group Homepage to check the Files, Bookmarks, Polls and other
> resources as they are often being updated. The page is at:
> 
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
> 
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> - Include your full name with your message.
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> 
>

Jerry,
 
I probably didn't explain enough my workflow: I never do 8 bit scans, I
always use 16 bit raw scans (i.e., with no curves/levels/other tweaks made
by scanner software). 
The choice for me is between converting this raw 16bit scan into 8 bits in
PS before starting to work on the picture, versus make all changes in 16 bit
mode. It's when comparing these two approaches that I can't see any
differences on screen.
I am sure that 8 bit scans have all the problems in the world (although I
don't know why converting from 16 to 8 in PS is better than scanning in 8
bits), but that's not what I was questioning.
By the way, drum scanners are out of reach for me :-) I use a Canon FS4000.
Anyway I'm sure that different scanners/software/printers/inks/printing
workflows may well make a difference, so I agree with you that everybody
should try on it's own equipment.
 
Alessandro Pardi

-----Original Message-----
From: Jerry Olson [mailto:jerryolson@...]
Sent: giovedì 23 maggio 2002 18.21
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: Re: [Digital BW] 8x16 bits and BW


Hi Allessandro,
  
Well on my images the noise in the shadows on the monitor is very
obvious when I scan a slide in 8 bits. If you make a large tone
adjustment in an 8 bit scan and then scan the same slide in 16 bits and
make the same adjustment, its obivous on my monitor that the 8 bit scan
is inferior. I don't have to make a print to prove it. Its almost always
that noise shows up in the shadows. Also splotches, or mottle. This
doesn't happen in 16 bit.

I realize this is image dependent, and wouldn't show up in all images.
It doesn't show up in ALL my images, and never in digital camera images.
I usually shoot the digital camera images in raw, make any curve
adjustments and then save it in 8 bits.  There isn't a posterization
problem at all with my Canon D30. In fact, I don't think I've ever seen
posterization in any image taken with the camera. Shadow detail with a
digital camera seems a lot better than with film, so It might not even
need the 16 bit raw image to begin with, but I do it anyway, just to be
safe.

It's much worse in scanning a black and white negative, and if I'm going
to make a large tonal adjustment, I MUST scan the negative in 16 bit.  

If you just scan and print and don't make any curve or level adjustments
at all, then it isn't nearly as bad, and in small prints, probably
wouldn't even show up.  A lot of images probably don't need a lot of
tonal adjustments. But I have this one particular client who insists on
using slow, contrasty films like velvia. And you have to make a real
effort to get acceptable (Not great, just acceptable) shadow detail,
requiring a very large curve adjustment. I just couldn't do it in 8 bit. 

I hope this discussion will result in people actually trying this for
themselves, and see the results on their own screens. If nobody can see
the difference, on their monitors, I must be doing something very
wrong!! I could have some setting wrong and that could be the cause. 

> I was rigorous, and I saw no difference *on screen*.

Maybe your scans are so good that you don't have the problem. I would
imagine a drum scan wouldn't have nearly the problems that ordinary
desktop filmscanners have.

Just out of curiosity,
> what do you think is the reason behind posterization showing up only on
the
> print? 

For me, I can see the difference on the monitor. It looks like mottled,
spotchy patches.

Jerry


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[Non-text portions of this message have been removed]

on 5/23/02 12:20 PM, Jerry Olson wrote:

> Hi Allessandro,
> 
> Well on my images the noise in the shadows on the monitor is very
> obvious when I scan a slide in 8 bits. If you make a large tone
> adjustment in an 8 bit scan and then scan the same slide in 16 bits and
> make the same adjustment, its obvious on my monitor that the 8 bit scan
> is inferior. I don't have to make a print to prove it. Its almost always
> that noise shows up in the shadows. Also splotches, or mottle. This
> doesn't happen in 16 bit.

Jerry

I think the discussion always assumes that if one is making side by side
comparisons one is manipulating files of equal quality, just different bit
depths. You're saying your 8-files start out at a distinct disadvantage to
your 16-bit files, so naturally they'll end up worse too.

But apparently each device will capture and process data differently, so
while one device will output a superb 8-bit file another will output a lousy
one. The danger is when we make sweeping generalizations about image editing
based on a few samples from any given device.

Obviously it's true that obtaining and keeping your data in 16-bit mode as
long as possible will be safest, and so long as the data is inside the
operation of the scanner you might has well keep it in 16-bit. There would
be no quality or convenience advantage to having your scanner capture and
manipulate 8-bit data when it can just as easily do it on 16-bit data.

However, once you have a quality scanned fully toned 16-bit file, is it
advantageous to keep it in 16-bit mode to perform any and all further or
local edits, or convert it to 8-bit where it's size is smaller and Photoshop
provides a full range of tools, layers and masks? It's worth it if it shows
up on output, but not if it doesn't.

I take a hybrid approach. I scan and do global edits in 16-bit, I save that
and then dupe the file and convert the dupe to 8-bit, where I apply local
and/or finer edits. I do this in 8-bit mode because I'm a layer and layer
mask freak! I can then go back and load those 8-bit adjustments on my 16-bit
data if necessary, but it's yet to be useful to do so.

That's not to say my prints are always good, just that using ONLY 16-bit
data has yet to be a fix for what was bad!!!

Todd

PS, If I ever get involved in another bit depth discussion, someone, please
someone, shoot me. ;-)

Hi Allesandro,

> ...(although I
> don't know why converting from 16 to 8 in PS is better than scanning in 8
> bits)

It depends on when you do your tonal curves.  Remember, most every scanner
is going to scan in ONLY high bit, it's how they work.  Typically, you have
a choice of 8 bit tone curve applied output, or raw output, but as I said,
both are scanned at the bit depth of the scanner, therefore there really is
no "scanning in 8 bits".

Austin

Todd,

> Why do you keep suggesting I conduct tests you know I've conducted many
> times over.

I knew you did some tests, but I do not remember what the results were.  I
am very busy, and have a LOT of things going on, so I'm sorry if I don't
remember the details here.

> You don't want to show your results, fine, just admit it,

I was only making a suggestion that others (there are other people in the
discussion I believe) should simply do the experiment for themselves.  I
have never had any problem showing my "results".  Too bad you didn't ask for
something like this before I sent you that package of prints, and I might
have been able to accommodate you easily at that time.

> but
> please stop telling me to do what you know I've done.

Sorry, I don't remember that you specifically did THESE tests for THIS
purpose.

> As for others, not everybody does have the capability to conduct these
> tests, and all they hear is "it's image dependant", or from you that your
> images posterize EASILY.

I did not say my images posterize easily.  I CAN make them posterize easily,
but that's not my goal.  I make corrections to make appropriate tonal
adjustments, not to posterize them.  What I found was that doing 8 bit tonal
manipulations DOES make some of the ones I did 8 bit manipulations to
posterize.

> My article demonstrated that many of my
> images can
> take robust manipulations without detriment

I will have to take the time to read your "article" then and understand what
it is you did.

How did you get the Leaf to give you an 8 bit scan without any tonal
correction?

> It could help to explain WHY there is debate at all on the subject,

Because someone made a claim that isn't entirely true.  Of course you can do
tonal manipulations on 8 bit files, and I've never said otherwise, but not
ALL images and not ALL tonal moves, without losing some tonality.  It's a
fact.  Why argue with it, when there is an easy solution that gives you
guaranteed results?  Do all the tonal manipulations you want in 8 bits if
you're happy with the results, I found I was not.

> Now, if you don't care enough to put the energy into it I FULLY understand
> that, but please stop making it seems like it's other peoples
> unwillingness.

That's absolutely not the case.  I feel it is better to have people learn to
do their own experiments properly and share the results.  I have shared my
results.  You apparently don't like my results, as they differ from yours.
I haven't seen YOUR prints, or the files or anything, I have from you just
what you have from me, your verbal results.

Regards,

Austin

Why does my scanner have the option to scan in either 16 or 8 bits then?
What would be the point?

I'm only talking about large tonal adjustments when I say the 16 is
always superior to 8 bit.

Jerry

> It depends on when you do your tonal curves.  Remember, most every scanner
> is going to scan in ONLY high bit, it's how they work.  Typically, you have
> a choice of 8 bit tone curve applied output, or raw output, but as I said,
> both are scanned at the bit depth of the scanner, therefore there really is
> no "scanning in 8 bits".

Hi Jerry,

> Why does my scanner have the option to scan in either 16 or 8 bits then?
> What would be the point?

Typically, the 8 bit scans apply the tonal curves in the scanner, and 16 bit
scans are raw scans, where no setpoints and tonal curves are applied in the
scanner.

But, as I said, no matter what your scanner does, it DOES scan using all the
bits the A/D has when it makes the scan.

Regards,

Austin

on 3/23/02 9:11 AM, Austin Franklin wrote:

Todd:
>> please stop telling me to do what you know I've done.

Austin: 
> Sorry, I don't remember that you specifically did THESE tests for THIS
> purpose.
 
<Snip>

Todd:
>> My article demonstrated that many of my
>> images can
>> take robust manipulations without detriment

Austin:
> I will have to take the time to read your "article" then and understand what
> it is you did.
> 
> How did you get the Leaf to give you an 8 bit scan without any tonal
> correction?

My mistake, Austin, when you sent me the message below I had just assumed
you actually read the piece. Plus, since we've exchanged dozens of posts on
this topic, spanning months and several lists, I assumed you'd check it (as
I included the link yesterday) before assuming what I did or did not do.
Ironically, when I wrote the damn thing I had hoped it would be an aid to
some of our discussions.

Anyway, I've always suspected you never really read my posts before
responding. <kidding>

on 3/23/02 9:11 AM, Austin Franklin wrote:

> A quick note/question on your write-up.  It's a very good write-up, BTW.  I
> don't believe the clips you are using at the bottom contain the top part of
> the histogram.  You have a white shirt collar in the image, and that would
> be quite a bit lighter than the eyes...so I believe that's the area that the
> very top part of the histogram would be representing, right?

> What do you think?  I histogramed those two images, and they both have full
> histograms, up until they cutoff, not having the white shirt collar in
> them...so even if the posterization exists in the .tiff files, it doesn't in
> the .jpegs...

> If you want a place to post the two .tiff images, you can use my FTP or web
> site. 

Interestingly, at that time you seemed to have found visual aids compelling
enough to ask for more from me, and you seemed to have a mechanism in place
to support it. Now when the same is asked of you, you tell me verbal
descriptions should be sufficient.

Look, I know it appears I'm taking you on - don't take it personally. I
really don't want, need, or expect, anything from you. I'm just showing the
course Dan's 16-bit challenge has run on many lists - LOTS of rhetoric, no
examples. I find it frustrating, but that's my problem, you are just doing
like everyone else.

Good night, and don't worry, I'm finished.

Todd

Hey Austin

I've been behaving rather petty and I'm not proud of it. My fault.

I'm off to get my head examined, or removed.

Todd

--- In DigitalBlackandWhiteThePrint@y..., Todd Flashner 
<tflash@e...> wrote:

> 
> Todd:
> >> My article demonstrated that many of my
> >> images can
> >> take robust manipulations without detriment
> 
> Todd

Hi Todd,

I'm kind of a late comer to the discussion, but I missed your
article first time around.  I went back and found it, read it and
have a couple ot things to add.

First of all, I was reluctant to get into the 8 bit challenge because
so much of it is subjective and unspecified.  What's a 
reasonable negative to be used, what's reasonable usage 
of the scanner, what's not too much tonal manipulation and 
how visible does the posterizing have to be.  Most people
could come up with a fabrication of posterization but then 
there's always the argument about whether the process
was "reasonable" i.e. could it happen in real work.

Todd's article at least is a reasonable place to start.  He shows
a fair amount of tonal manipulation in 8 bit mode and shows
results that at least on the surface are surprisingly good.

There are several factors that I think may make the result look
better than it expected.  I can't really be sure these would
make a difference but maybe Todd can tell from the originals.

1)  To make the images fit in the article, they were shrunk
to 50%.  I assume this was cropping and resampling down
in PS.  This means that 4 pixels in the original where averaged
into 1 pixel in the output.  By doing this, the gaps are effectively
filled in partially.  If there was a jump in the histogram from
100 to 120 its possible that 105, 110, and 115 levels were
generated by the averaging.

2) In the html of the article the images are again shrunk
slightly by about 82%.  This means the browsers are again
resampling and averaging all the pixels.

3) Compressing with jpg also slightly changes all the levels.
The uncompressed files are never identical to the original.

All these may seem small individually, but as was observed
if you read the jpg's into PS and look at the histograms, they
are completely filled up except for going all the way to white.

---------

The next issue I think is the choice of image and cropping.
The image is great for showing some need for tonal
manipulation, while not overly drastic the changes to create
some combing in the histogram.  The other major issue is
that posterization is only going to be obvious in a very
gradual gradation of tone.  Detail like hair is great for sharpness
but won't show posterization no matter what you do to it.

So here's my idea:  Let's keep the picture and the tonal
corrections, but let's add a slow gradient at the bottom.  I took
the original jpg from the article and added a PS gradient 
from 40%K to 0%K below.  I just did the light end since
the corrections make it darker and also the posterizing is
likely in the white end.

Now I applied the tonal changes that Todd had in his article.
Well sure enough the gradient shows very obvious posterization
right on the screen.  This was all done in 8 bit mode.

I figured I ought to try it in 16 bit mode.  First problem is that
the gradient tool doesn't work in 16 bit mode.  So I put the
gradient in in 8 bit mode, converted to 16 bit, and then ran
a gaussian blur with radius 4.  This put at least some
data down into the lower bits, but I know of no way to "see"
what those lower bits are.  Rerunning the tonal changes
there was no posterization with the 16 bit mode and the
histogram was jagged but pretty much filled up.

----------------------------------

So, does this prove anything?  Probably depends on what
you want to think.  I tried to show that what might look OK
could potentially also result in problems.

For me, I figure that the raw scan must be done in greater
than 8 bits (12 to 16 or so), most tonal changes should be
done in high bit mode but once they are done conversion
to 8 bit is OK before printing.  This conversion can be done
in the scanner software and just pass on 8 bit to PS, or
we can pass all the high bits to PS and delay the conversion
as long as desired.  You just have to decide when "most"
tonal changes are finished.

Roy

Roy, 

Thanks for your comments on my write-up. You raise good points, many of
which were noted by others the first time around.

Your comments on the subjective nature of the challenge are all extremely
valid. Unfortunately I think the challenge was concocted to to get the ball
rolling, to induce people to get involved in the conversation, to show their
images and results; but in the end people just got too hung-up on the
specifics of it to play. They took a "challenge" as a fight, and chose to
stay away. But it seems even a $100 "reward" doesn't do the trick either, so
there's just no way to win. Anyway, those challenges are for color images
and we are here for BW, but the same subjective conditions do apply. I
simply did my piece to take up the call to demonstrate some results through
images, even if it's not an entry into THE challenge.

With that said, I put a lot of energy into trying to define the scenario in
my piece and not enough into images. I could post 100% TIFFs and will try
to, but somehow I trashed my original images, so I'll have to regenerate
them, which is what's slowing me up. Ugh, another project...

The thing is, as you say, all images will respond differently, and my hope
really was that some others might be inspired to take their own images and
do something similar. Then we can get a sense of what may happen across a
broader image base. I think that would be better than getting bogged down in
my one image. I fear I'll never choose an image, select a crop, or
manipulate the file, etc, to everyone's liking, so we'll see. Maybe my piece
is done as is and someone else can do it better...

As for including a grayscale image, the inestimable Antonis also suggested
that, so I may try to include that if I do a revision. Here my fear is that
people will fixate on a posterized gradient, without regard to how grain,
detail, noise, etc, - IOW, the components of an image that differentiate a
photo from a pure gradient - mitigate the effects of posterization. Most
beginners believe that blurring and smoothing an image will mitigate
posterization, when in fact it's the opposite - adding noise (randomization)
is the fix. That's why PS adds dither when converting between modes. That
dither IS one reason that images sometimes look better than we think they
should.

You also listed several factors, notably image downsampling and JPG
compression, as factors that could have made my images look better than
expected. This raises a question from me. If you have the time to test this
I'd be extremely interested if you would try to replicate those processes on
your pure and posterized gradient images, and either post them or describe
the effect. That might go a long way toward confirming or denying those as
relevant factors.

Thanks Roy,

Todd



on 5/25/02 12:38 AM, royvharrington wrote:

> Hi Todd,
> 
> I'm kind of a late comer to the discussion, but I missed your
> article first time around.  I went back and found it, read it and
> have a couple ot things to add.

> First of all, I was reluctant to get into the 8 bit challenge because
> so much of it is subjective and unspecified.  What's a
> reasonable negative to be used, what's reasonable usage
> of the scanner, what's not too much tonal manipulation and
> how visible does the posterizing have to be.  Most people
> could come up with a fabrication of posterization but then
> there's always the argument about whether the process
> was "reasonable" i.e. could it happen in real work.
> 
> Todd's article at least is a reasonable place to start.  He shows
> a fair amount of tonal manipulation in 8 bit mode and shows
> results that at least on the surface are surprisingly good.
> 
> There are several factors that I think may make the result look
> better than it expected.  I can't really be sure these would
> make a difference but maybe Todd can tell from the originals.
> 
> 1)  To make the images fit in the article, they were shrunk
> to 50%.  I assume this was cropping and resampling down
> in PS.  This means that 4 pixels in the original where averaged
> into 1 pixel in the output.  By doing this, the gaps are effectively
> filled in partially.  If there was a jump in the histogram from
> 100 to 120 its possible that 105, 110, and 115 levels were
> generated by the averaging.
> 
> 2) In the html of the article the images are again shrunk
> slightly by about 82%.  This means the browsers are again
> resampling and averaging all the pixels.
> 
> 3) Compressing with jpg also slightly changes all the levels.
> The uncompressed files are never identical to the original.
> 
> All these may seem small individually, but as was observed
> if you read the jpg's into PS and look at the histograms, they
> are completely filled up except for going all the way to white.
> 
> ---------
> 
> The next issue I think is the choice of image and cropping.
> The image is great for showing some need for tonal
> manipulation, while not overly drastic the changes to create
> some combing in the histogram.  The other major issue is
> that posterization is only going to be obvious in a very
> gradual gradation of tone.  Detail like hair is great for sharpness
> but won't show posterization no matter what you do to it.
> 
> So here's my idea:  Let's keep the picture and the tonal
> corrections, but let's add a slow gradient at the bottom.  I took
> the original jpg from the article and added a PS gradient
> from 40%K to 0%K below.  I just did the light end since
> the corrections make it darker and also the posterizing is
> likely in the white end.
> 
> Now I applied the tonal changes that Todd had in his article.
> Well sure enough the gradient shows very obvious posterization
> right on the screen.  This was all done in 8 bit mode.
> 
> I figured I ought to try it in 16 bit mode.  First problem is that
> the gradient tool doesn't work in 16 bit mode.  So I put the
> gradient in in 8 bit mode, converted to 16 bit, and then ran
> a gaussian blur with radius 4.  This put at least some
> data down into the lower bits, but I know of no way to "see"
> what those lower bits are.  Rerunning the tonal changes
> there was no posterization with the 16 bit mode and the
> histogram was jagged but pretty much filled up.
> 
> ----------------------------------
> 
> So, does this prove anything?  Probably depends on what
> you want to think.  I tried to show that what might look OK
> could potentially also result in problems.
> 
> For me, I figure that the raw scan must be done in greater
> than 8 bits (12 to 16 or so), most tonal changes should be
> done in high bit mode but once they are done conversion
> to 8 bit is OK before printing.  This conversion can be done
> in the scanner software and just pass on 8 bit to PS, or
> we can pass all the high bits to PS and delay the conversion
> as long as desired.  You just have to decide when "most"
> tonal changes are finished.
> 
> Roy

on 5/25/02 3:32 AM, Todd Flashner wrote:

> You also listed several factors, notably image downsampling and JPG
> compression, as factors that could have made my images look better than
> expected. This raises a question from me. If you have the time to test this
> I'd be extremely interested if you would try to replicate those processes on
> your pure and posterized gradient images, and either post them or describe
> the effect. That might go a long way toward confirming or denying those as
> relevant factors.

Actually, there is one problem with this test. Detail. You said these
maneuvers might have my images look better than expected. In a smooth
gradient you might see what effect they have on posterization, but you
couldn't correlate it to the preservation of detail and sharpness that shows
in my images. IOW, blurring and softening moves are only effective at
"improving" images if they mitigate posterization WITHOUT destroying
sharpness and detail. Without some detail being processed alongside those
gradients I think it'd be hard to tell what positive or negative effect
those moves might have on a real image.

Todd