Digital BW, The Print

Hi Roy

I have just finished (finally) calculating and loading some softproofs for Permajet Alpha.  
The softproofing capability is great.  Thanks to you and to Carl!  One question comes to 
mind again though and it has to do with the way QTR prints a lot lighter than the image on 
screen.  The softproofing feature highlights this dramatically.  I find I have to punch the 
blacks to get close to a match (duplicating the image on screen with one softproofed and 
the other not).  Thinking out loud, given the two end points are fixed, ie paper white and 
100% black, this begs the question as to whether something is out of whack in the original 
curve linearisation process.  Either that or QTR/Gimp maps pixels with a bias away from 
100%.  In general, I would expect the softproof to only show me (a) the hue of the output 
paper and ink combo and (b) the lower dmax (assuming out-of-gamut is not an issue).  A 
curve adjustment can't alter (b) cos 100% black is as black as can be. What am I missing?

Cheers

Steve

PS:  Do you check simulate paper white in the softproof? (I have not but many in the colour 
world argue you should)

Hi Steve,

I'm not sure I can give you much theory behind it all.   I mostly go by whatever
looks and works the best.  I've always been surprised by how poor a simple
21step looks on a well profiled monitor.   On the other hand the softproofed
21step has much nicer separation everywhere and matches the print too.
On the Piezo website the rollovers that show their softproofing exhibit the
same dramatic tonal difference.  I don't know why but softproofing is so good
as far as I'm concerned that I just use it all the time.

I would think "simulate paper white" would be correct, too.  But again by trying
both it just doesn't look as good.  With EEM the highlights look way to blue.
So I leave paper white and ink black off.

Roy

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Steve Kale" 
<stevekale@b...> wrote:
> Hi Roy
> 
> I have just finished (finally) calculating and loading some softproofs for Permajet 
Alpha.  
> The softproofing capability is great.  Thanks to you and to Carl!  One question 
comes to 
> mind again though and it has to do with the way QTR prints a lot lighter than the 
image on 
> screen.  The softproofing feature highlights this dramatically.  I find I have to punch 
the 
> blacks to get close to a match (duplicating the image on screen with one 
softproofed and 
> the other not).  Thinking out loud, given the two end points are fixed, ie paper 
white and 
> 100% black, this begs the question as to whether something is out of whack in the 
original 
> curve linearisation process.  Either that or QTR/Gimp maps pixels with a bias away 
from 
> 100%.  In general, I would expect the softproof to only show me (a) the hue of the 
output 
> paper and ink combo and (b) the lower dmax (assuming out-of-gamut is not an 
issue).  A 
> curve adjustment can't alter (b) cos 100% black is as black as can be. What am I 
missing?
> 
> Cheers
> 
> Steve
> 
> PS:  Do you check simulate paper white in the softproof? (I have not but many in the 
colour 
> world argue you should)

Roy, thanks for the response.  I agree that soft proofing works well.  The
interesting thing is that I tend to work on an image without it and then
turn it on when it comes to printing.  I then find a curve that I think best
turns the image back to how it looked with proofing off (the premise being I
might want to print to different media) which is inherently a little hit and
miss.  Still can¹t help thinking that this undoes something that was done
before.  I was wondering if there was a sort of gamut compression factor
(lay man¹s terms) going on.  That is, if the monitor can represent a scale
of 0 to 100 whereas say the printer can only produce 10 to 80 (paper not
being perfect white and the inks not being able to get perfect black). (The
10 and the 80 are measured as part of the linearisation process.)  If the
driver, curves and linearisation process then mapped 0 to 10 and 100 to 80
and all else in between proportionately then there would be quite a tonal
shift.  A pixel originally at 75 would get thumped down to 65.  This would
all cause an image to trend to mid gray and print a lot lighter.  What I
think we would prefer to have happen is that the 75 stays at 75 and an 85
pixel simply hits the max of 80.  Just thinking out loud....

From: "Roy Harrington" <roy@...>

Hi Steve,

I'm not sure I can give you much theory behind it all.   I mostly go by
whatever
looks and works the best.  I've always been surprised by how poor a simple
21step looks on a well profiled monitor.   On the other hand the softproofed
21step has much nicer separation everywhere and matches the print too.
On the Piezo website the rollovers that show their softproofing exhibit the
same dramatic tonal difference.  I don't know why but softproofing is so
good
as far as I'm concerned that I just use it all the time.

I would think "simulate paper white" would be correct, too.  But again by
trying
both it just doesn't look as good.  With EEM the highlights look way to
blue.
So I leave paper white and ink black off.

Roy




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

I am having a terrible time with QTR on my Epson 7000.  On Panther (10.3.4),
I removed all traces of QTR and Gimp Print, reinstalled QTR, and I was able
to print one sheet. But as soon as I either restart the computer or the
printer, the Mac can no longer see the printer. Every time I restart the
printer, the Print Center ³sees² the printer as a new ³Epson 7000 QTR Gimp
print 4.25² printer (but can¹t print to it!).  If I try to (option) add a
new printer, Print Center doesn¹t see the printer.

I did a new install of Jaguar, hoping that that would solve the problem.
Again, I was able to print one sheet, but had to turn the printer on and
off, and after that the problems re-surfaced again.

Has anyone had similar problems, and can anyone offer any suggestions?

Thanks for any help in advance.


Bill Morse
PhotoProspect
343 Medford St., Studio 2A
Somerville, MA 02145
(617) 868-7642



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

Hi Bill,

I have a 7500 running on Panther without any significant troubles.
However, there are a couple things that could be giving you trouble.

First is that there is a USB/7000 incompatility in Panther.  On my website
look for the patch that installs some code from Jaguar.  When you upgrade
new Panther releases you have to redo this patch. (hopefully it'll be fixed=
).

Second, on rare occasions I've seen a timing glitch of the computer sleepin=
g
or waking up together with the printer power up/down that leaves things in
a hung state.  Simple 3 Second Reset on the printer has always worked for m=
e.

Last you could have a hardware connection problem.  Use the shortest cord
without hubs -- just try different connections to see if it changes results=
.

----

If these don't get you running, there are several software diagnostics that=

may pinpoint the problem.  Contact me offgroup.

Roy

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Bill Morse <willym@b..=
.> 
wrote:
> I am having a terrible time with QTR on my Epson 7000.  On Panther (10.3.=
4),
> I removed all traces of QTR and Gimp Print, reinstalled QTR, and I was ab=
le
> to print one sheet. But as soon as I either restart the computer or the
> printer, the Mac can no longer see the printer. Every time I restart the
> printer, the Print Center ³sees² the printer as a new ³Epson 7000 QTR Gim=
p

> print 4.25² printer (but can¹t print to it!).  If I try to (option) add a=

> new printer, Print Center doesn¹t see the printer.
> 
> I did a new install of Jaguar, hoping that that would solve the problem.
> Again, I was able to print one sheet, but had to turn the printer on and
> off, and after that the problems re-surfaced again.
> 
> Has anyone had similar problems, and can anyone offer any suggestions?
> 
> Thanks for any help in advance.
> 
> 
> Bill Morse
> PhotoProspect
> 343 Medford St., Studio 2A
> Somerville, MA 02145
> (617) 868-7642
> 
> 
> 
> [Non-text portions of this message have been removed]

Steve,

I think you are right that there is a "gamut compression" going on.  But
I think there's a basic fitting of one gamut into another happening no
matter what.  I'm not even sure how you'd compare a 75 gray in a file, a 75=

gray on the screen and a 75 gray on paper in absolute terms.  What are
the units?

Although I can see you point in your 10 to 80 example, I'm not to sure
trying to do things "absolute" is great either.  Wouldn't you result in all=

the values from 80 to 100 being mapped to the same max 80 density?
Maintaining the best separation you can throughout seems like a better
alternative.   This is analogous to the color rendering -- using Perceptual=

rather than Absolute Colormetric.

Roy

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale <stevekale@=
b...> 
wrote:
> Roy, thanks for the response.  I agree that soft proofing works well.  Th=
e
> interesting thing is that I tend to work on an image without it and then
> turn it on when it comes to printing.  I then find a curve that I think b=
est
> turns the image back to how it looked with proofing off (the premise bein=
g I
> might want to print to different media) which is inherently a little hit =
and
> miss.  Still can¹t help thinking that this undoes something that was done=

> before.  I was wondering if there was a sort of gamut compression factor
> (lay man¹s terms) going on.  That is, if the monitor can represent a scal=
e
> of 0 to 100 whereas say the printer can only produce 10 to 80 (paper not
> being perfect white and the inks not being able to get perfect black). (T=
he
> 10 and the 80 are measured as part of the linearisation process.)  If the=

> driver, curves and linearisation process then mapped 0 to 10 and 100 to 8=
0
> and all else in between proportionately then there would be quite a tonal=

> shift.  A pixel originally at 75 would get thumped down to 65.  This woul=
d
> all cause an image to trend to mid gray and print a lot lighter.  What I
> think we would prefer to have happen is that the 75 stays at 75 and an 85=

> pixel simply hits the max of 80.  Just thinking out loud....
> 
> 
> From: "Roy Harrington" <roy@h...>
> 
> Hi Steve,
> 
> I'm not sure I can give you much theory behind it all.   I mostly go by
> whatever
> looks and works the best.  I've always been surprised by how poor a simpl=
e
> 21step looks on a well profiled monitor.   On the other hand the softproo=
fed
> 21step has much nicer separation everywhere and matches the print too.
> On the Piezo website the rollovers that show their softproofing exhibit t=
he

> same dramatic tonal difference.  I don't know why but softproofing is so
> good
> as far as I'm concerned that I just use it all the time.
> 
> I would think "simulate paper white" would be correct, too.  But again by=

> trying
> both it just doesn't look as good.  With EEM the highlights look way to
> blue.
> So I leave paper white and ink black off.
> 
> Roy
> 
> 
> 
> 
> [Non-text portions of this message have been removed]

I think I would rather have all values between 80-100 be 80.  At least the
80 value will be 80 and a 90 be at least as black as possible.  (And all
units from 0 to 10 will be as white as possible.)  There will of course be
some loss of shadow detail but this is simply because it is beyond the
rendition ability of the printer, ink and paper combination (in the same way
that it can¹t produce a 5 because the paper isn¹t white enough).  Better
this than a complete remap of the tone of the image and in effect lightening
the whole image so that we retrieve the shadow (and highlight) detail at the
margin (which we likely reverse with a curve at the time of proofing).  Put
another way, if we are happy with 80 as a deep enough black then we will not
be too worried that a 90 only prints at 80.  (Of course the goal is to find
an ink and paper combination that is capable of expanding my 10 to 80 space
to a perfect 0 to 100.)  I suspect this is all much more of an issue in B&W
with its simpler colour space, particularly when we typically drive for
contrast with deep blacks offset with strong highlights.  A flat grey image
is exactly what we don¹t want.  In a colour image there is a lot more going
on and the various ways of dealing with out-of-gamut colours are more
appropriate.   I agree that there should be good separation between 10 and
80 so that we get a good ability to print in-gamut shades of grey.  The
question is what happens at either end and the impact on the image of
dealing with this.  As for units, I guess I am thinking of RGB values or any
other means of measuring a grey scale space.  I used 0 to 100 as a simple
description.  I guess in RGB these would be equal R, G and B values from 0
to 255. 

From: "Roy Harrington" <roy@...>

Steve,

I think you are right that there is a "gamut compression" going on.  But
I think there's a basic fitting of one gamut into another happening no
matter what.  I'm not even sure how you'd compare a 75 gray in a file, a 75=

gray on the screen and a 75 gray on paper in absolute terms.  What are
the units?

Although I can see you point in your 10 to 80 example, I'm not to sure
trying to do things "absolute" is great either.  Wouldn't you result in all=

the values from 80 to 100 being mapped to the same max 80 density?
Maintaining the best separation you can throughout seems like a better
alternative.   This is analogous to the color rendering -- using Perceptual=

rather than Absolute Colormetric.





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

You can get an idea of the differences with a few small PS experiments.
Take a nice full range B&W image.  Go into adjust curves.
Drag the 0,0 point to 10,10 and drag 100,100 to 80, 80
You ought to have a horizontal lines from 10,10 to the edge and
80,80 to the edge.  This is the change you are proposing.
Click Preview on and off to see the changes.  Shadows and Highlights
are clipped but the mid range stays the same.
Now move the points out to the edge along the horizontal lines.  The 
Input values will now be 0 and 100.  This shows the other way.  It
lightens the picture but there is no clipping.

Its a personal choice which you like, but my tendency is to go with the
readjustment to avoid clipping. 

My point about units was that 0 to 255 has no meaning for ink on paper.
The amount of light reflecting from paper depends on the light striking it.=

I was trying to say there are no absolute units that can relate to both
paper and a screen.

Roy

--- In DigitalBlackandWhiteThePrint@...m, Steve Kale <stevekale@=
b...> 
wrote:
> I think I would rather have all values between 80-100 be 80.  At least th=
e
> 80 value will be 80 and a 90 be at least as black as possible.  (And all
> units from 0 to 10 will be as white as possible.)  There will of course b=
e
> some loss of shadow detail but this is simply because it is beyond the
> rendition ability of the printer, ink and paper combination (in the same =
way
> that it can¹t produce a 5 because the paper isn¹t white enough).  Better
> this than a complete remap of the tone of the image and in effect lighten=
ing
> the whole image so that we retrieve the shadow (and highlight) detail at =
the
> margin (which we likely reverse with a curve at the time of proofing).  P=
ut
> another way, if we are happy with 80 as a deep enough black then we will =
not
> be too worried that a 90 only prints at 80.  (Of course the goal is to fi=
nd
> an ink and paper combination that is capable of expanding my 10 to 80 spa=
ce
> to a perfect 0 to 100.)  I suspect this is all much more of an issue in B=
&W
> with its simpler colour space, particularly when we typically drive for
> contrast with deep blacks offset with strong highlights.  A flat grey ima=
ge
> is exactly what we don¹t want.  In a colour image there is a lot more goi=
ng
> on and the various ways of dealing with out-of-gamut colours are more
> appropriate.   I agree that there should be good separation between 10 an=
d
> 80 so that we get a good ability to print in-gamut shades of grey.  The
> question is what happens at either end and the impact on the image of
> dealing with this.  As for units, I guess I am thinking of RGB values or =
any
> other means of measuring a grey scale space.  I used 0 to 100 as a simple=

> description.  I guess in RGB these would be equal R, G and B values from =
0
> to 255. 
> 
> 
> From: "Roy Harrington" <roy@h...>
> 
> Steve,
> 
> I think you are right that there is a "gamut compression" going on.  But
> I think there's a basic fitting of one gamut into another happening no
> matter what.  I'm not even sure how you'd compare a 75 gray in a file, a =
75=
> 
> gray on the screen and a 75 gray on paper in absolute terms.  What are
> the units?
> 
> Although I can see you point in your 10 to 80 example, I'm not to sure
> trying to do things "absolute" is great either.  Wouldn't you result in a=
ll=
> 
> the values from 80 to 100 being mapped to the same max 80 density?
> Maintaining the best separation you can throughout seems like a better
> alternative.   This is analogous to the color rendering -- using Perceptu=
al=

> 
> rather than Absolute Colormetric.
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]

Agreed.  Although I am surprised you prefer the look of the second curve.
The slope of the curve (gamma) has been dramatically flattened and an image
will look washed out and lack contrast.  Put another way, the whole image
has been brightened so that the image detail at the margin can be restored.
In  the former, the tonal relationships are preserved as much as possible
but yes there is loss of shadow and highlight detail because it is beyond
the scope of the ink-media combination.   I am also not sure how the
mid-point is affected in the second scenario.  That is, is the curve
straight or curved around a stable 50-50 midpoint?  I will bet that most
people when confronted with the second scenario when soft-proofing end up
applying an s-curve that deepens the dark areas of the print and lightens
the lighter areas in effect making the resultant combined affect of the
image much closer to the former scenario (test this by doing the second and
then altering this curve until you are happy with the look of the image
again.)  Personally, I would find it an easier workflow to have the former
happen....highlight and shadow detail gets clipped to reflect the minimum
dmax of the paper and maximum dmax of 100% black.  I could then decide how
much I was prepared to lighten the image and lower contrast to restore some
of the detail at the margin.  Anyway, food for thought.....

From: "Roy Harrington" <roy@...>

You can get an idea of the differences with a few small PS experiments.
Take a nice full range B&W image.  Go into adjust curves.
Drag the 0,0 point to 10,10 and drag 100,100 to 80, 80
You ought to have a horizontal lines from 10,10 to the edge and
80,80 to the edge.  This is the change you are proposing.  Click Preview on
and off to see the changes.  Shadows and Highlights
are clipped but the mid range stays the same.  Now move the points out to
the edge along the horizontal lines.  The
Input values will now be 0 and 100.  This shows the other way.  It
lightens the picture but there is no clipping.  Its a personal choice which
you like, but my tendency is to go with the
readjustment to avoid clipping.




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

On another note, are you guys using the 21 steps for constructing your soft
proof  profiles or the 51s?



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

I can't say I'm all that enamored with either one.   So I probably ought
to think about it some more.

BTW, I've always used just the 21step for softproofing.

Roy

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale <stevekale@b...> 
wrote:

> Agreed.  Although I am surprised you prefer the look of the second curve.
> The slope of the curve (gamma) has been dramatically flattened and an image
> will look washed out and lack contrast.  Put another way, the whole image
> has been brightened so that the image detail at the margin can be restored.
> In  the former, the tonal relationships are preserved as much as possible
> but yes there is loss of shadow and highlight detail because it is beyond
> the scope of the ink-media combination.   I am also not sure how the
> mid-point is affected in the second scenario.  That is, is the curve
> straight or curved around a stable 50-50 midpoint?  I will bet that most
> people when confronted with the second scenario when soft-proofing end up
> applying an s-curve that deepens the dark areas of the print and lightens
> the lighter areas in effect making the resultant combined affect of the
> image much closer to the former scenario (test this by doing the second and
> then altering this curve until you are happy with the look of the image
> again.)  Personally, I would find it an easier workflow to have the former
> happen....highlight and shadow detail gets clipped to reflect the minimum
> dmax of the paper and maximum dmax of 100% black.  I could then decide how
> much I was prepared to lighten the image and lower contrast to restore some
> of the detail at the margin.  Anyway, food for thought.....
> 
> From: "Roy Harrington" <roy@h...>
> 
> You can get an idea of the differences with a few small PS experiments.
> Take a nice full range B&W image.  Go into adjust curves.
> Drag the 0,0 point to 10,10 and drag 100,100 to 80, 80
> You ought to have a horizontal lines from 10,10 to the edge and
> 80,80 to the edge.  This is the change you are proposing.  Click Preview on
> and off to see the changes.  Shadows and Highlights
> are clipped but the mid range stays the same.  Now move the points out to
> the edge along the horizontal lines.  The
> Input values will now be 0 and 100.  This shows the other way.  It
> lightens the picture but there is no clipping.  Its a personal choice which
> you like, but my tendency is to go with the
> readjustment to avoid clipping.
> 
> 
> 
> 
> [Non-text portions of this message have been removed]