Digital BW, The Print

----- Original Message -----
From: "jimhayes361" <jimhayes@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Tuesday, June 25, 2002 12:58 PM
Subject: [Digital BW] Re: pshop 6->7 VM (converts file differently?)



(snip earlier)

> 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.
>
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.

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