Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., Todd Flashner <tflash@e...> 
wrote:
> on 6/25/02 1:37 PM, jimhayes361 wrote:
> 
> > I would 
> > guess this is due to either a change in the way layers are merged 
when
> > converting to RGB, a change in the way the data is converted from
> > gamma 2.2 to sRGB, or a change in the way Paul's curve is applied 
as
> > an adjustment layer.
> 
> I don't have PS 7 so I don't know if the Color Settings dialog is 
the same,
> but... 
> 
> in the Advanced section, are you using the same Conversion Engine 
(Adobe Ace
> is probably your best choice, though perhaps that is what got 
tweaked and
> upgraded between versions. Try Apple CMM with both versions and 
compare),
> Intent, Black Point Compensation, and Dither, settings? If any of 
these
> settings are different between versions you will get different 
conversions
> between modes.
> 
> Todd


Todd,

The complete color settings advanced  dialouge is IDENtical for both 
ver 6 and ver 7 when I did the histogram test. I used Adobe ace 
relative colometric, with black point and dither boxes checked. I 
can't try Apple CMM, I don't seem to have it as an option on Windows, 
all I could try is Microsoft ICM- I figured it would just buy me more 
trouble knowing how great ms is at color matching<g>.

The workflow, selections in all dialog boxes, presets, order of 
workflow, file, curve loaded, etc etc...was done identically for both 
ver 6 and 7 AFAIK. And the same done mutiple times through the 
workflow. But please, I welcome anyone checking me out on this so that 
I can resolve my posterization problem.

The steps I did after making sure that color settings ("pshop 5 
defaults" settings), etc were identical:
1) Open file up, disgarding mismatched profile. Image is labelled 
"untagged grey". I could assign profile of gamma 2.2 to it, but it 
just gives me the same  histogram results.

2) convert to rgb mode. Dialog asks if I wantt to merge layers. I 
choose "yes". sRGB appears as the new color space for file.

3) Add adjust curves layer- in curves dialog I load Paul's mw 2880 
curve for PC. I also checked the normal 1440 (mw for PC 1280) curve 
that most people use  and also get a change from 6 to 7.

4) select background layer and view histogram. Note down mean, SD and 
median.

5) close down pshop and open up the other version and repeat steps. 
There is a slight discrepancy in all three values, but most notable in 
the median.
Jim H.