wwp@yahoogroups.com:
Re: Java on PC/MAC (was Re: Origins of the Panorama view)
Francis Fougere 2005-Jan-19 18:30:00
> An issue that concerns me is the discrepancy between the default
> gamma of Mac (1.8) and PC (2.2) monitors that causes images on the PC
> to appear darker than on the Mac. Any suggestions, anyone?
> --
>
> Uri Cogan
Hi Uri
Your gamma issues as described above have been discussed elsewhere on a
different list server to which I belong to. I have copied the discussion
below as I could not have explained it any better myself. I have been
involved in getting photography to the ink on paper process for twenty years
and I have found Andrew Rodney's advise to be spot on.
Francis Fougere
The following was copied from an other list server. For information about
joining these lists or contact info please contact me at #removed#
yo dudesz...
i just had a very enlightening discussion for the good people at
gretagmacbeth,
where i was encouraged to change the Gamma of my Apple Monitor from 1.8 to
2.2...
it was explained to me that the Gamma of 1.8 for your Apple monitor was
first determined for an old Apple Laser Printer that no longer exists
today...
setting your monitor to a Gamma of 2.2 may more accurately represent the
deep rich blacks that can be with todays modern desktop printers...
talk to you soon...
--
Mark
www.prorental.com
Correct. The 1.8 gamma legacy is kind of dumb (especially in light of OSX
when Apple could have just gone to 2.2). It does date back to gamma response
of the old LaserWriter on a 1 bit display.
Displays don't really have a gamma per say (they have a tone response curve
which provide a measurement in gamma). Most LCDs and CRTs have a native TRC
gamma of about 2.2. Certainly closer than 1.8!
The farther you get to the native behavior of the display system, the more
compensation has to take place at the video card LUT (Look Up Table). So
with an 8-bit LUT (in nearly all cases), you're doing a lot more correction
when you calibrate (force the display) into 1.8 than 2.2. The results are
more banding and other issues.
Mac users should do one of two things. First, calibrate to 2.2 not 1.8.
Better yet is to measure the NATIVE gamma of the display and calibrate to
that. It might be 2.1 or 2.2 or 2.3 or a fraction of that. 2.2 is close
enough although with the Sony Artisan you can actually tell the software to
aim for the specific and unique gamma of that display.
Downside to this for Mac users is the OS "assumes" 1.8 so anything you view
that's not ICC aware will look a bit dark. It's not a big deal. Photoshop
will gladly handle the disconnect in gamma from the OS since it's using the
display profile which "knows" how the unit was set.
> setting your monitor to a Gamma of 2.2 may more accurately represent the
> deep rich blacks that can be with todays modern desktop printers...
The gamma here however doesn't play a role with the printer or output
device. That's all handled by the output profile.
Ah, the gamma of the working space and the display have no relation and
don't have to match. The gamma of a working space is simply that, the input
to output values of that color space. There's no reason why you can't aim
for a gamma of 2.2 for the display and use a 1.8 gamma in a working space
like that found in ColorMatch RGB or ProPhoto RGB. A 2.2 gamma in a working
space is more perceptually uniform but that's not anything to really lie
awake at night worrying about.
Andrew Rodney
http://digitaldog.net/