Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., "Martin Wesley" 
<mwesley250@e...> wrote:
> 

> Jim,
> 
> I went through the steps above (except that I am working in Adobe 
RGB) and I
> am not seeing any significant difference between 6 and 7
> 
> For the PS7 version of my file I got Mean = 124.58, Std. Dev. = 
95.52,
> Median = 143
> For the PS6 version of my file I got Mean = 124.41, Std. Dev. = 
95.48,
> Median = 143
> 
> So there is some difference but much smaller than you are getting. I 
am
> running Windows 2000. I wonder if it is image dependent.

Martin I think this is the case exactly. I did a few images since I 
switched to PS7 and most were normal range prints- that is a more or 
less full tonal spectrum. It's really hard to see and I didn't think I 
had a problem at all, except the  small areas of shadow values looked 
a little posterized which I figured was just bad file manipulation on 
my part.

But I just went back and reprinted a print which is just about all 
shadows. For example your mean is about 124, about midrange, or, a 
fully balanced tonal image. My mean is 46.83 (ps6) or 45.57 (ps7). I 
also find it interesting that your histogram discrepancy is less than 
mine- is it due to darkness of print or do I have a setting wrong?

Now this dark print I originally printed in Febuary. More than about 
80% of it's surface is shadow detail, and it is one of my best prints 
as far as smooth shadow values/ transistions go. There is absolutely 
no posterization in the 3/4 tones which take up a lot of the print 
surface.

When I compare it to the print I just reprinted yesterday in PS7- the 
new print is really bad. I have a close up of a hand with skin texture 
but it is very dark skin (varies Zone  III-IV) . in this new print 
instead of a textured hand I get something that is so posterized it 
almost looks like a cartoon.

In addition I have a silklike drape that covers much of the 
background. Smooth in tonal transistion in the Febuary print,  in the 
print yesterday the tone breaks lighter suddenly on a fold of the 
cloth where it looks like it's broken out with measles.

Anyway, my supposition (not even a theory yet) is that if you don't 
get exactly the same numbers in PS7 vs 6, even if they are off less 
than 1%, the file is still different than the one you fed to the 
printer under PS6. Perhaps the higher values around 70%k say are not 
as sensitive to small changes in the file data. But how can anyone say 
how much of a difference in the histogram values will affect what 
Paul's curves do to image?

The only way to solve this is to first, make sure I am not overlooking 
something in my settings/workflow, and then when I get the VM ink back 
in, simply print out my dark "problem" print in both PS 6 and in PS 7 
and see if it does print shadows differently. This is the only final 
way to rule it out or in.

However, I am gratefull for your giving me Culbertsons workflow 
notion, and I think I will go back to the puter and try it out.

Sorry for the length. If you get a chance and have some time, try 
printing out one of your lowest key images and check for posterization 
in 3/4 tones. I don't know if it would show up in a step wedge, I 
suspect if one compared it side by side, 6 vs 7 it might.
Thanks for the help,
Jim H.   


> 
> The only thing I can suggest was a recommendation from Dan 
Culbertson way
> back on converting from grayscale to RGB. The workflow would go: 
flatten
> image, mode change to Channels, delete any remaining alpha channels,
> duplicate the black channel twice so that there are three black 
channels,
> convert to RGB. The theory is that this will reduce the chance of 
any gamma
> mismatch between the grayscale space and RGB space. Something to 
try.
> 
> Martin