Digital BW, The Print

Hello all,

There has been something I have noticed when I changed from Gray 
Gamma 2.2 to Gray Gamma 1.8. When I have the 21 step grayscale which 
has the density marked in percentages,and I pass the eyedropper tool 
over the 50% square and am using GG 1.8; the number of the percentage 
is 58% and the number relative to 0 to 255 is 148. If I reset the 
Gray Gamma to 2.2 the numbers match the grayscale markings.I have 
come to realize the grayscale was intended to be viewed at GG 2.2. 
Does anyone have a grayscale that is calibrated with the numbers to 
be viewed at GG 1.8. Even the grayscale from PiezographyBW is marked 
like the GG 2.2 scale and Jon Cones recommends the monitor and the 
workspace of Photoshop both be GG 1.8. Has anyone else dealt with 
this question and resolved it to their satisfaction yet? If so please 
share with this group. I wouldn't think I was the only one noticing 
this anomaly.

Your answer seeking friend in Photography,

Johnny

> From: Johnny Eades [mailto:jeades1@...]
> 
> There has been something I have noticed when I changed from Gray 
> Gamma 2.2 to Gray Gamma 1.8. When I have the 21 step grayscale which 
> has the density marked in percentages,and I pass the eyedropper tool 
> over the 50% square and am using GG 1.8; the number of the percentage 
> is 58% and the number relative to 0 to 255 is 148. If I reset the 
> Gray Gamma to 2.2 the numbers match the grayscale markings.I have 
> come to realize the grayscale was intended to be viewed at GG 2.2. 
> Does anyone have a grayscale that is calibrated with the numbers to 
> be viewed at GG 1.8. Even the grayscale from PiezographyBW is marked 
> like the GG 2.2 scale and Jon Cones recommends the monitor and the 
> workspace of Photoshop both be GG 1.8. Has anyone else dealt with 
> this question and resolved it to their satisfaction yet? If so please 
> share with this group. I wouldn't think I was the only one noticing 
> this anomaly.

Just assign the 1.8 profile, instead of converting to it.

-- 

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...

Hello Paul,

GG 1.8 is my working gray profile defined in color settings in 
Photoshop. The monitor is set at GG 1.8 and Photoshop is set at GG 
1.8. The 21 step grayscale is showing 148 at 50% at GG 1.8, and it 
shows 127 at GG 2.2 (if I assign it GG 2.2). I do all of my work at 
GG 1.8 now. I just am curious as to the reason for the majority of 
the Grayscales I've seen using 127 as the 50% reading.I someone had a 
monitor set at GG 1.8 and didn't know it, they would have a hard time 
getting the numbers to match the grayscale; wouldn't they?


Your friend in Photography,

Johnny





--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul D. 
DeRocco" <pderocco@i...> wrote:
> > From: Johnny Eades [mailto:jeades1@s...]
> > 
> > There has been something I have noticed when I changed from Gray 
> > Gamma 2.2 to Gray Gamma 1.8. When I have the 21 step grayscale 
which 
> > has the density marked in percentages,and I pass the eyedropper 
tool 
> > over the 50% square and am using GG 1.8; the number of the 
percentage 
> > is 58% and the number relative to 0 to 255 is 148. If I reset the 
> > Gray Gamma to 2.2 the numbers match the grayscale markings.I have 
> > come to realize the grayscale was intended to be viewed at GG 
2.2. 
> > Does anyone have a grayscale that is calibrated with the numbers 
to 
> > be viewed at GG 1.8. Even the grayscale from PiezographyBW is 
marked 
> > like the GG 2.2 scale and Jon Cones recommends the monitor and 
the 
> > workspace of Photoshop both be GG 1.8. Has anyone else dealt with 
> > this question and resolved it to their satisfaction yet? If so 
please 
> > share with this group. I wouldn't think I was the only one 
noticing 

> > this anomaly.
> 
> Just assign the 1.8 profile, instead of converting to it.
> 
> -- 
> 
> Ciao,               Paul D. DeRocco
> Paul                mailto:pderocco@i...

> From: Johnny Eades [mailto:jeades1@...]
>
> GG 1.8 is my working gray profile defined in color settings in
> Photoshop. The monitor is set at GG 1.8 and Photoshop is set at GG
> 1.8. The 21 step grayscale is showing 148 at 50% at GG 1.8, and it
> shows 127 at GG 2.2 (if I assign it GG 2.2). I do all of my work at
> GG 1.8 now. I just am curious as to the reason for the majority of
> the Grayscales I've seen using 127 as the 50% reading.I someone had a
> monitor set at GG 1.8 and didn't know it, they would have a hard time
> getting the numbers to match the grayscale; wouldn't they?

It sounds like you're trying to make things more complicated than they are.
If it shows 148 at 50% at gamma 1.8, and 127 at gamma 2.2, then you didn't
assign the profile, you converted to it. Assigning doesn't touch the
numbers, it just redefines them; converting changes the numbers to keep the
same appearance in the new space.

The main thing I use step wedges for is to see if there are any faint color
casts in certain parts of the scale. So I don't know what you mean by "they
would have a hard time getting the numbers to match the grayscale." What
numbers, or what grayscale? Are you talking about trying to use a step wedge
as a guide for manually tweaking the monitor to match some print? If so,
then it depends upon how you printed the print, and how you're displaying
the wedge on the screen. If everything is color managed (e.g., if you're
viewing in, and printing from, Photoshop, then it doesn't matter what the
gamma of the image is, because it will be corrected for automatically, both
for printing and for display. If, however, you're viewing the wedge in a
non-color-managed application, then, yes, you'll have to make sure that you
assign the proper gamma when printing, to match the nominal gamma of your
display.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...

Johnny,

When you are looking at the 127 or 148 values you are looking at the
RGB conversion of the grayscale value.  The reason you are getting
different values when GG is 1.8 rather than 2.2 is that they convert
differently to the working RGB space.   You probably have Adobe RGB for the
RGB space which is a gamma 2.2 space, so a 50% K value in GG 1.8
(which internally is 127) will convert to 148 in the Adobe RGB space
and that's what you will see in the Info palette.

My recommendation would be to use the same gamma in both GS and
RGB.   Gamma 1.8 would correspond to Apple RGB, and Gamma 2.2
would correspond to Adobe RGB.   

There's a hidden feature in Photoshop to see the gamma of an RGB space:
  select the RGB space you want in Color Settings.
  then select the same pull down again but go to Custom RGB ...
  you will see the details of the previously selected RGB space.

Roy



--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Johnny Eades" 
<jeades1@s...> wrote:

> Hello Paul,
> 
> GG 1.8 is my working gray profile defined in color settings in 
> Photoshop. The monitor is set at GG 1.8 and Photoshop is set at GG 
> 1.8. The 21 step grayscale is showing 148 at 50% at GG 1.8, and it 
> shows 127 at GG 2.2 (if I assign it GG 2.2). I do all of my work at 
> GG 1.8 now. I just am curious as to the reason for the majority of 
> the Grayscales I've seen using 127 as the 50% reading.I someone had a 
> monitor set at GG 1.8 and didn't know it, they would have a hard time 
> getting the numbers to match the grayscale; wouldn't they?
> 
> 
> Your friend in Photography,
> 
> Johnny
> 
> 
> 
> 
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul D. 
> DeRocco" <pderocco@i...> wrote:
> > > From: Johnny Eades [mailto:jeades1@s...]
> > > 
> > > There has been something I have noticed when I changed from Gray 
> > > Gamma 2.2 to Gray Gamma 1.8. When I have the 21 step grayscale 
> which 
> > > has the density marked in percentages,and I pass the eyedropper 
> tool 
> > > over the 50% square and am using GG 1.8; the number of the 
> percentage 
> > > is 58% and the number relative to 0 to 255 is 148. If I reset the 
> > > Gray Gamma to 2.2 the numbers match the grayscale markings.I have 
> > > come to realize the grayscale was intended to be viewed at GG 
> 2.2. 
> > > Does anyone have a grayscale that is calibrated with the numbers 
> to 
> > > be viewed at GG 1.8. Even the grayscale from PiezographyBW is 
> marked 
> > > like the GG 2.2 scale and Jon Cones recommends the monitor and 
> the 
> > > workspace of Photoshop both be GG 1.8. Has anyone else dealt with 
> > > this question and resolved it to their satisfaction yet? If so 
> please 
> > > share with this group. I wouldn't think I was the only one 
> noticing 
> > > this anomaly.
> > 
> > Just assign the 1.8 profile, instead of converting to it.
> > 
> > -- 
> > 
> > Ciao,               Paul D. DeRocco
> > Paul                mailto:pderocco@i...