Digital BW, The Print

----- Original Message -----

From: "royvharrington" <roy@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Wednesday, April 03, 2002 7:57 PM
Subject: Re: [Digital BW] Thoughts about Imaging


(snip)
>
> Dynamic Range is a characterization how much bigger the maximum intensity
is
> from the minimum intensity of the system.  In sound that's the ratio of
the loudest
> to the quietest.  In an image that's the ratio of the brightest to the
darkest.
> Austin's ratio is of the high contrast to the lowest contrast.

Roy,

Ratio of minimum and maximum contrast. You have hit the nail on the head!
This fulfils the basic definition and is not as obtuse as it would appear
from the DyR equation. The equation is just a subtle change on the basic max
to min ratio but makes a great deal of sense in systems where noise is a
major factor in discriminating between signal levels. Austin is not wrong in
applying his contrast ratio to a photographic print but he has failed to
demonstrate how this would be done or what value it would have when
comparing two printing mediums.

Thanks,
Martin

(snip)

> Ratio of minimum and maximum contrast.

B-b-b-b-b-but Martin, isn't maximum contrast (dMax - dMin), and minimum
contrast the "smallest discernable [tonality]"?

> This fulfils the basic definition and is not as obtuse as it would appear
> from the DyR equation.

For photographic use, I'd agree with that!

> The equation is just a subtle change on
> the basic max
> to min ratio

What's the change?  The definition of "min" and "max"?

<snip>

> Austin is
> not wrong in
> applying his contrast ratio to a photographic print but he has failed to
> demonstrate how this would be done or what value it would have when
> comparing two printing mediums.

For me, that's a separate issue...I wanted to get to the point where the
basic concept was understood first.  I take it you now understand/agree with
the statement "dynamic range of a photographic image is (maximum contrast /
minimum contrast)", and not the same as the density range?

Regards,

Austin

----- Original Message -----

From: "Austin Franklin" <darkroom@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Wednesday, April 03, 2002 9:15 PM
Subject: RE: For Roy Re: [Digital BW] Thoughts about Imaging


>
> > Ratio of minimum and maximum contrast.
>
> B-b-b-b-b-but Martin, isn't maximum contrast (dMax - dMin), and minimum
> contrast the "smallest discernable [tonality]"?

Austin,

The problem I have is what is doing the discerning. I know that my eye
cannot discern as small a change in tone as a densitometer for example. Also
if the print changes tones in increments smaller than my eye can detect,
then the minimum contrast would be determined by my eye and not the print.
The idea of min/max contrast perhaps makes some sense to me but I am still
skeptical of how it could be put to good use.  I need to mull this over a
bit.
>
> > This fulfils the basic definition and is not as obtuse as it would
appear
> > from the DyR equation.
>
> For photographic use, I'd agree with that!
>
> > The equation is just a subtle change on
> > the basic max
> > to min ratio
>
> What's the change?  The definition of "min" and "max"?

No it is a clarification of what we are taking the dynamic range of. The
dynamic range of contrast would not appear to be the same as the dynamic
range of density.
>
> <snip>
>
> > Austin is
> > not wrong in
> > applying his contrast ratio to a photographic print but he has failed to
> > demonstrate how this would be done or what value it would have when
> > comparing two printing mediums.
>
> For me, that's a separate issue...I wanted to get to the point where the
> basic concept was understood first.  I take it you now understand/agree
with
> the statement "dynamic range of a photographic image is (maximum contrast
/
> minimum contrast)", and not the same as the density range?

I better understand the relationship you are trying to define but I have
long realized that it was something different from the density range. Now as
to which is the more useful concept I am not sure. Would it be inappropriate
for a print to have more than one dynamic range? Each for different
properties or relationships between those properties? Or perhaps the word
dynamic range has been used in so many different ways we need some new
terminology?

Martin

It seems to me that we have usefully isolated two different ways you can
potentially measure the tonal qualities of a print. The first

(1)    D1 = Dmax - Dmin

measures the difference between the brightest and darkest parts of a
print. I think we all have an instinctive feel for what a big number
versus a small number means here. In this context Dmax represents the log
density of the darkest black, Dmin the log density of the whitest white,
presumably the paper base.

The second

(2)    D2 = Cmax - Cmin

where C is a log measure of contrast, measures the difference between the
greatest contrast a printer can render, and the smallest. (In my opinion
this needs to include some criterion of how large an area we are talking
about, in order to take into account the coarseness or otherwise of the
dither, but that's a side issue).

I'm assuming here that 

(3)    Cmax = Dmax - Dmin.

I'm also assuming that 

(4)    Cmin = Dmin' - Dmin

where Dmin' is the lightest tone the printer is capable of rendering
which is distinguishable above the 'noise level' or natural tonal
variation of the paper base.

Plugging (3) and (4) into (2) gives

(5)     D2 = Dmax - Dmin'


Now the question here is not which of these, D1 or D2, is properly called
Dynamic Range, but whether there is a useful difference between them?

For example, what are the perceptual differences between two prints with
different values of D2? Does it really measure tonal smoothness? We need
some concrete examples to be able to decide that I think.

I'm going to reply to my own post here because I think I was wrong, or not
as right as I could have been.

On 4/4/02 7:12 AM, "John Brownlow" <lists@...> wrote:

> The second
> 
> (2)    D2 = Cmax - Cmin
> 
> where C is a log measure of contrast, measures the difference between the
> greatest contrast a printer can render, and the smallest. (In my opinion
> this needs to include some criterion of how large an area we are talking
> about, in order to take into account the coarseness or otherwise of the
> dither, but that's a side issue).
> 
> I'm assuming here that
> 
> (3)    Cmax = Dmax - Dmin.
> 
> I'm also assuming that
> 
> (4)    Cmin = Dmin' - Dmin
> 
> where Dmin' is the lightest tone the printer is capable of rendering
> which is distinguishable above the 'noise level' or natural tonal
> variation of the paper base.

Actually, I think you can make this (sort of) independent of the paper.

Equation (3) becomes:

(3a)    Cmax = Dmax - Dmin'

Where Dmin' is defined as above.

Equation (4) becomes:

(4a)    Cmin = MIN ( delta (D) )

That looks a bit intimidating but all I mean is that it is the minimum
possible value of (D1-D2) where D1 and D2 are two different tones output by
the printer. In other words the smallest possible difference in contrast the
printer is reliably capable of achieving (or the visual noise floor of the
paper, whichever is larger).

Actually measuring Cmin on an 8-bit printer is not that difficult. All you
need is a 16x16 checkerboard representing brightness values 1-256. You
measure them all and find the difference between the two whose density
values are closest together.

However I'm not sure what this would tell you. Wouldn't it be more useful to
see what the *maximum* density difference between two *adjacent* gray cells
was? This would genuinely be a measure of the coarseness of the contrast
since any big jumps here would appear as posterisation in the final print.
Relating this to Dmax is clearly relevant, too.

Eg

(4b)    Cmin = MAX ( delta (Dn, Dn+1) )

Where Dn is the density of a patch of gray representing brightness level n
(between 1 and 2**n in an n-bit grayscale image)

> Plugging (3) and (4) into (2) gives
> 
> (5)     D2 = Dmax - Dmin'

Or in this case

(5a)    D2 = (Dmax - Dmin') - MAX ( delta (Dn, Dn+1))

This seems like an achievable measurement and definitely different from the
original D1 in equation (1). I wonder what, if anything, it really tells us?


-- 
John Brownlow

http://www.pinkheadedbug.com

Hi Martin,

> > > Ratio of minimum and maximum contrast.
> >
> > B-b-b-b-b-but Martin, isn't maximum contrast (dMax - dMin), and minimum
> > contrast the "smallest discernable [tonality]"?
>
> Austin,
>
> The problem I have is what is doing the discerning. I know that my eye
> cannot discern as small a change in tone as a densitometer for
> example. Also
> if the print changes tones in increments smaller than my eye can detect,
> then the minimum contrast would be determined by my eye and not the print.
> The idea of min/max contrast perhaps makes some sense to me but I am still
> skeptical of how it could be put to good use.  I need to mull this over a
> bit.

I understand and agree.

<snip>

> > > The equation is just a subtle change on
> > > the basic max
> > > to min ratio
> >
> > What's the change?  The definition of "min" and "max"?
>
> No it is a clarification of what we are taking the dynamic range of. The
> dynamic range of contrast would not appear to be the same as the dynamic
> range of density.

Hum.  I had to read that a few times.  In a way I agree.  Density is a
static value, and really can be only a single value in and of it self
(though it's understood it is a relative value, based on a calibrated
density scale...).  Contrast isn't static...it requires another thing to be
contrasted against.  In that, I agree...and fits the term "dynamic" much
better.

> > <snip>
> >
> > > Austin is
> > > not wrong in
> > > applying his contrast ratio to a photographic print but he
> has failed to
> > > demonstrate how this would be done or what value it would have when
> > > comparing two printing mediums.
> >
> > For me, that's a separate issue...I wanted to get to the point where the
> > basic concept was understood first.  I take it you now understand/agree
> with
> > the statement "dynamic range of a photographic image is
> (maximum contrast
> /
> > minimum contrast)", and not the same as the density range?
>
> I better understand the relationship you are trying to define but I have
> long realized that it was something different from the density
> range. Now as
> to which is the more useful concept I am not sure.

We are in full agreement and understanding here ;-)

> Would it be
> inappropriate
> for a print to have more than one dynamic range? Each for different
> properties or relationships between those properties? Or perhaps the word
> dynamic range has been used in so many different ways we need some new
> terminology?

I do believe the dynamic range of the printing system can be determined, as
well as of the paper one is printing on.  Quite easily in fact.  Obviously,
as has been well pointed out, the actual dynamic range of A print, in and of
it self, is a far more complex issue.  I agree.  I have to sit with that for
a while when I get some time.  I believe I understand how it can be done,
but obviously, haven't spent the time doing it.  It would be interesting (at
least to me) though.

Regards,

Austin

on 4/4/02 10:27 AM, John Brownlow wrote:

<Snip>
 
> (5a)    D2 = (Dmax - Dmin') - MAX ( delta (Dn, Dn+1))
> 
> This seems like an achievable measurement and definitely different from the
> original D1 in equation (1). I wonder what, if anything, it really tells us?

John,

I followed along as best I could, but I did get lost (not understanding
delta and all), but here's the deal. By the time you've measured all your
256 density patches, what do you want to do with that data? Do you want to
compress it all into a value like 2.6, or 25db, that really tells you very
little about the characteristics of your print (short of suggesting a
density range), or would you rather plot it as a curve (which is how I've
always seen silver papers characteristics represented), to get a more
meaningful representation of the qualities of said print?

Even with scanners, where Austin's DyR formula is totally applicable, what
does the net result really tell you? The density range the scanner is
capable of before noise becomes intrusive. In electronics we can't see the
noise from outside of the box; on a print, if the noise is the tooth of the
paper, do you really want that characteristic expressed as a number?

Plus much of this discussion so far has focused on the ability of a paper to
separate the first perceptible highlight from dMin. What does it say about a
paper like Somerset Enhanced, which has soft smooth midtones, which some
might crave, in spite of what may be high "noise" and relatively weak
highlight separation? Could you appreciate that characteristic from a single
number?

Ironically, a paper like Torchon, which has a lot of surface modulation,
yields one of the sharpest looking prints out there, at least for larger
prints. And the tooth of that paper seems to be relatively more of a problem
to our visual perception than I'm guessing one would expect from measured
values. So some people hate it for small prints with close viewing
distances, but love it for larger prints with far viewing distances. What do
we do with that?

Todd

On 4/4/02 11:42 AM, "Todd Flashner" <tflash@...> wrote:

>> This seems like an achievable measurement and definitely different from the
>> original D1 in equation (1). I wonder what, if anything, it really tells us?
> 
> John,
> 
> I followed along as best I could, but I did get lost (not understanding
> delta and all), but here's the deal. By the time you've measured all your
> 256 density patches, what do you want to do with that data? Do you want to
> compress it all into a value like 2.6, or 25db, that really tells you very
> little about the characteristics of your print (short of suggesting a
> density range), or would you rather plot it as a curve (which is how I've
> always seen silver papers characteristics represented), to get a more
> meaningful representation of the qualities of said print?

I by delta (d1,d2) I just mean (d1-d2) if (d1>d2) and (d2-d1) if (d2>d1)

Ie 'the positive value of the difference between'

I would much rather see a plot, as you suggest, but I am trying to suggest a
mathematical basis for the alternative definition of dynamic range we've
seen.
-- 
John Brownlow

http://www.pinkheadedbug.com

John,

I think that your idea has merit from a technical point of view but I
suspect that in practice we would get lost at the point our eyes cannot
distinguish between Dmin and D'min. This would only seem to be of interest
if it was clearly visible to some degree. I think that in quality silver and
inkjet prints the difference between Dmin and D'min is lost to the eye, or
at least my eyes anyways.

Martin

----- Original Message -----
From: "John Brownlow" <lists@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Thursday, April 04, 2002 7:27 AM
Subject: Re: [Digital BW] Some equations WAS Thoughts about Imaging


> I'm going to reply to my own post here because I think I was wrong, or not
> as right as I could have been.
>
> On 4/4/02 7:12 AM, "John Brownlow" <lists@...> wrote:
>
> > The second
> >
> > (2)    D2 = Cmax - Cmin
> >
> > where C is a log measure of contrast, measures the difference between
the
> > greatest contrast a printer can render, and the smallest. (In my opinion
> > this needs to include some criterion of how large an area we are talking
> > about, in order to take into account the coarseness or otherwise of the
> > dither, but that's a side issue).
> >
> > I'm assuming here that
> >
> > (3)    Cmax = Dmax - Dmin.
> >
> > I'm also assuming that
> >
> > (4)    Cmin = Dmin' - Dmin
> >
> > where Dmin' is the lightest tone the printer is capable of rendering
> > which is distinguishable above the 'noise level' or natural tonal
> > variation of the paper base.
>
> Actually, I think you can make this (sort of) independent of the paper.
>
> Equation (3) becomes:
>
> (3a)    Cmax = Dmax - Dmin'
>
> Where Dmin' is defined as above.
>
> Equation (4) becomes:
>
> (4a)    Cmin = MIN ( delta (D) )
>
> That looks a bit intimidating but all I mean is that it is the minimum
> possible value of (D1-D2) where D1 and D2 are two different tones output
by
> the printer. In other words the smallest possible difference in contrast
the
> printer is reliably capable of achieving (or the visual noise floor of the
> paper, whichever is larger).
>
> Actually measuring Cmin on an 8-bit printer is not that difficult. All you
> need is a 16x16 checkerboard representing brightness values 1-256. You
> measure them all and find the difference between the two whose density
> values are closest together.
>
> However I'm not sure what this would tell you. Wouldn't it be more useful
to
> see what the *maximum* density difference between two *adjacent* gray
cells
> was? This would genuinely be a measure of the coarseness of the contrast
> since any big jumps here would appear as posterisation in the final print.
> Relating this to Dmax is clearly relevant, too.
>
> Eg
>
> (4b)    Cmin = MAX ( delta (Dn, Dn+1) )
>
> Where Dn is the density of a patch of gray representing brightness level n
> (between 1 and 2**n in an n-bit grayscale image)
>
> > Plugging (3) and (4) into (2) gives
> >
> > (5)     D2 = Dmax - Dmin'
>
> Or in this case
>
> (5a)    D2 = (Dmax - Dmin') - MAX ( delta (Dn, Dn+1))
>
> This seems like an achievable measurement and definitely different from
the
> original D1 in equation (1). I wonder what, if anything, it really tells
us?
>
>
> --
> John Brownlow
>
> http://www.pinkheadedbug.com
>
>
>
> 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/
>
>
>

Austin,

I am not sure I have much to add at this point. Still mulling things over.
Charles Francis wrote me off list and brought up the term "internal
contrast(s)" which I am familiar with. Sometime just thought of as "local
contrast". This can be a problem in prints where the overall contrast
balances out nicely in the print but there will be some area typically with
fine detail of interest that covers just a tiny portion of the density range
and winds up looking like mud. This seems to be a common problem with
contracted developments where there has been a strong compression of tone
from the scene to the negative. Is this in anyway related to what you see in
the quality of the tonality of the print?

Martin

----- Original Message -----
From: "Austin Franklin" <darkroom@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Thursday, April 04, 2002 8:41 AM
Subject: RE: For Roy Re: [Digital BW] Thoughts about Imaging


> Hi Martin,
>
> > > > Ratio of minimum and maximum contrast.
> > >
> > > B-b-b-b-b-but Martin, isn't maximum contrast (dMax - dMin), and
minimum
> > > contrast the "smallest discernable [tonality]"?
> >
> > Austin,
> >
> > The problem I have is what is doing the discerning. I know that my eye
> > cannot discern as small a change in tone as a densitometer for
> > example. Also
> > if the print changes tones in increments smaller than my eye can detect,
> > then the minimum contrast would be determined by my eye and not the
print.
> > The idea of min/max contrast perhaps makes some sense to me but I am
still
> > skeptical of how it could be put to good use.  I need to mull this over
a
> > bit.
>
> I understand and agree.
>
> <snip>
>
> > > > The equation is just a subtle change on
> > > > the basic max
> > > > to min ratio
> > >
> > > What's the change?  The definition of "min" and "max"?
> >
> > No it is a clarification of what we are taking the dynamic range of. The
> > dynamic range of contrast would not appear to be the same as the dynamic
> > range of density.
>
> Hum.  I had to read that a few times.  In a way I agree.  Density is a
> static value, and really can be only a single value in and of it self
> (though it's understood it is a relative value, based on a calibrated
> density scale...).  Contrast isn't static...it requires another thing to
be
> contrasted against.  In that, I agree...and fits the term "dynamic" much
> better.
>
> > > <snip>
> > >
> > > > Austin is
> > > > not wrong in
> > > > applying his contrast ratio to a photographic print but he
> > has failed to
> > > > demonstrate how this would be done or what value it would have when
> > > > comparing two printing mediums.
> > >
> > > For me, that's a separate issue...I wanted to get to the point where
the
> > > basic concept was understood first.  I take it you now
understand/agree
> > with
> > > the statement "dynamic range of a photographic image is
> > (maximum contrast
> > /
> > > minimum contrast)", and not the same as the density range?
> >
> > I better understand the relationship you are trying to define but I have
> > long realized that it was something different from the density
> > range. Now as
> > to which is the more useful concept I am not sure.
>
> We are in full agreement and understanding here ;-)
>
> > Would it be
> > inappropriate
> > for a print to have more than one dynamic range? Each for different
> > properties or relationships between those properties? Or perhaps the
word
> > dynamic range has been used in so many different ways we need some new
> > terminology?
>
> I do believe the dynamic range of the printing system can be determined,
as
> well as of the paper one is printing on.  Quite easily in fact.
Obviously,
> as has been well pointed out, the actual dynamic range of A print, in and
of
> it self, is a far more complex issue.  I agree.  I have to sit with that
for
> a while when I get some time.  I believe I understand how it can be done,
> but obviously, haven't spent the time doing it.  It would be interesting
(at
> least to me) though.
>
> 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/
>
>
>

on 4/5/02 1:52 AM, Martin Wesley wrote:

> Austin,
> 
> I am not sure I have much to add at this point. Still mulling things over.
> Charles Francis wrote me off list and brought up the term "internal
> contrast(s)" which I am familiar with. Sometime just thought of as "local
> contrast". This can be a problem in prints where the overall contrast
> balances out nicely in the print but there will be some area typically with
> fine detail of interest that covers just a tiny portion of the density range
> and winds up looking like mud. This seems to be a common problem with
> contracted developments where there has been a strong compression of tone
> from the scene to the negative. Is this in anyway related to what you see in
> the quality of the tonality of the print?
> 
> Martin

See if these clarify anything. I doubt they will, I think they'll point to
the the complexity of all this:

*******
Abstract

This paper is an attempt to integrate a wide variety of psychophysical
experiments into a computational model to calculate color appearance. Having
described the fundamentals of such a model, we turn to applying this model
to printing wide dynamic range, real-life scenes and finding the best
reproduction of an image with limited printer gamut.

<http://www.imaging.org/pubs/reporter/articles/14_6_mccann/index.cfm>


*******
Nonlinear Effect of Modulation on Image Quality
Petet Barten, Barten Consultency

In most image quality metrics, a linear relation is assumed between
modulation and perceived image quality. However, in practice it appears that
this relation is nonlinear. Granger and Cupery (1972) found at their
investigation of photographic pictures, that there is a linear relation
between the subjectively perceived image quality and the number of
just-noticeable differences. From our investigation of sinusoidal luminance
patterns, we found that the number of just-noticeable differences is
proportional to the square root of the modulation. The constant in this
relation becomes independent of spatial frequency if the modulation is
divided by the threshold modulation. From measurements by Cannon (1985), we
found that this rule also holds for the subjectively perceived contrast of
sinusoidal luminance patterns, in agreement with measurements by Watanabe et
al.(1968). The above given principles are used in the square-root integral
or SQRI for the description of image quality. In this method a logarithmic
integration over spatial frequency is applied to account for the
contribution of the different spatial frequency components of an image to
the total image quality. Here, various examples of measured image quality
will be given which will illustrate the given rules.
Peter Barten studied physics at the Technical Univ. of Delft and worked at
Philips in Eindhoven, where he was in charge of the development of color
CRTs. In 1987 he became an independent consultant and developed the SQRI
method for the evaluation of perceived image quality, and a model for the
spatio-temporal contrast sensitivity of the human eye. He is the author of a
recent book on the contrast sensitivity of the human eye and its effects on
image quality. In 1999 he received a Ph.D. degree from the Technical Univ.
of Eindhoven. 

<http://www.imaging.org/conferences/pics2002/keynote.html>

******

Todd

> I by delta (d1,d2) I just mean (d1-d2) if (d1>d2) and (d2-d1) if (d2>d1)
> 
> Ie 'the positive value of the difference between'

Hi Johnny,

Wouldn't that be "absolute value"?

Regards,

Austin

On 4/5/02 11:11 AM, "Austin Franklin" <darkroom@...> wrote:

>> I by delta (d1,d2) I just mean (d1-d2) if (d1>d2) and (d2-d1) if (d2>d1)
>> 
>> Ie 'the positive value of the difference between'
> 
> Hi Johnny,
> 
> Wouldn't that be "absolute value"?

yes
-- 
John Brownlow

http://www.pinkheadedbug.com

> >> I by delta (d1,d2) I just mean (d1-d2) if (d1>d2) and (d2-d1) 
> if (d2>d1)
> >> 
> >> Ie 'the positive value of the difference between'
> > 
> > Hi Johnny,
> > 
> > Wouldn't that be "absolute value"?
> 
> yes
> -- 
> John Brownlow

Thank you Johnny, glad for ONCE I could simplify something for someone ;-)

Regards,

Austin

> Austin,
>
> I am not sure I have much to add at this point. Still mulling things over.
> Charles Francis wrote me off list and brought up the term "internal
> contrast(s)" which I am familiar with. Sometime just thought of as "local
> contrast". This can be a problem in prints where the overall contrast
> balances out nicely in the print but there will be some area
> typically with
> fine detail of interest that covers just a tiny portion of the
> density range
> and winds up looking like mud. This seems to be a common problem with
> contracted developments where there has been a strong compression of tone
> from the scene to the negative. Is this in anyway related to what
> you see in
> the quality of the tonality of the print?
>
> Martin

Hi Martin,

Yes, I believe is a related and important issue, and I can think of how to
interrelate it, but I'm a bit tired to try to do it now ;-)

Regards,

Austin