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Digital BW, The Print

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Message

Re: Run PS 6 & 7?BUG?

2003-01-11 by jim hayes <jimhayes@frii.com>

In the color settings dialogue just make sure you have gamma 2.2 
selected for greyscale space and sRGB selected for RGB space (if you 
choose "Adobe photoshop 5 defaults" at the top you get this 
automatically). Set this in both ver 6 and ver 7. Then get a dark file 
and write down the hist numbers- there will be a small diff but it 
still means that the two versions are converting differently.

Then go back to color settings and change RGB space to Adobe98 and see 
how the histonumbers are identical, or much more close anyway.

You can also just create a file with patches from 90%k to 100%k or use 
Paul's step wedge in files section of this group. You will see the 
most innacuracy in conversion in this region(95%k).

It affects a minority of photos, but I got posterization in shadows 
with VM curves. Many folks have no problem. The solution is to use 
pshop 6 to print, or alter Paul's curves in pshop 7 IF based on sRGB 
(lucky MAC folks don't use sRGB for 1280 but windows folks do, unless 
this has changed since June). Or simply use Adobe98 for the space in 
pshop 7 and see how it works.
Jim H.



--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Vincent Orlando 
<orlandovl@h...>" <orlandovl@h...> wrote:
> 
> Jim, I assume the conversion is done in the color settings or is 
> there somewhere else I can convert without changing the color 
> settings? Sorry if I sound uninformed about all the intricacysof PS
> 
> Vinny
> http://wulfsdden.com
> 
> 
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "jim hayes 
> <jimhayes@f...>" <jimhayes@f...> wrote:
> > Take a file in greyscale with gamma 2.2 space, preferably one with 
> a 
> > lot of dark to it. Convert it to sRGB in both PS6 and PS7 Each 
time 
> > write down the histogram statistics (mean, median, std deviation). 
> See 
> > how they differ in PS7 but not in PS6? That's the bug. Try 
> converting 
> > to Adobe RGB 98 space. See how they now will differ very little, 
if 
> at 
> > all in either version? So if using Paul's curves and PS7, avoid 
> > converting to sRGB space- use Adobe RGB 98.
> > Jim H. 
> > 
> > 
> > 
> > 
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Vincent 
> Orlando 
> > <orlandovl@h...>" <orlandovl@h...> wrote:
> > > 
> > > What bug are you talking about? I have been using PS7 and 
> converting 
> > > both ways nd using Paul's curves with no problem
> > > 
> > > Vinny
> > > http://www.wulfsden.com
> > > 
> > > 
> > > 
> > > 
> > > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Editor 
> P.O.V. 
> > > Image Service" <editor@p...> wrote:
> > > > I use both on the same machine in WinXP Pro// Just make sure 
> you 
> > > don't 
> > > > install them to the same directory.  Oh, and you can't open 
one 
> if 
> > > the 
> > > > other is already running.. It just never opens the second app.
> > > > 
> > > > ... BUT with the KNOWN Greyscale to RGB conversion bug, I use 
6 
> > for 
> > > all 
> > > > my B&W to RGB conversions, as well as most of my Greyscale 
> work... 
> > > I 
> > > > have this silly thing against unintended posterization or 
muddy 
> > > prints.  
> > > > 
> > > > If you look back through the archives here you will find the 
> > > conversion 
> > > > bug is documented AND a problem if you are using the Roark 
> > > workflow. 
> > > >  Adobe has said they will NOT fix the bug in 7.x..
> > > > 
> > > > Keith
> > > > 
> > > >  
> > > > 
> > > > "Just some guy," and caretaker of the Multiverse's largest 
> EPSON 
> > > printer 
> > > > User Community (highly recommended by Vogon Poets and MegaDodo 
> > > > Publications), at:
> > > > 
> > > > http://groups.yahoo.com/group/EPSONx7x_Printers/
> > > >  
> > > > "For the rest of you out there, the secret is to bang the 
rocks 
> > > together 
> > > > guys"
> > > > 
> > > >  
> > > > 
> > > > 
> > > > { The P.O.V. Image Service Website is still at 
http://www.p-o-v-
> > > image.com/ }
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > [Non-text portions of this message have been removed]

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