Re: Gamma settings for monitors
Re: Gamma settings for monitors
- Subject: Re: Gamma settings for monitors
- From: Roger Breton <email@hidden>
- Date: Wed, 18 Jul 2001 08:38:36 -0400
Rich,
My understanding is that, on the Mac, the "native" gamma turns out to be 1.8
according to a document written by Charles Poynton called "Gamma correction
on the Apple Macintosh" -- I do not have the URL handy for it but it's not
too hard to find on the net if you look for it in Google.
In general, for the Mac gamma, one usually finds the argument that 1.8
agreed better with the gamma of the original LaserWriter output. Maybe that
is still true today. I have not testesd that assertion myself yet. But the
direction I am taking today -- others may disagree with me on other
theoretical or practical grounds -- is that, regardless of the gamma I
choose to work in (at the time of calibrating my monitor with ProveIt! and
my DTP-92), what matters to me is that the digital counts in my video card
is mapped at the right intensity value on my display. I have not completely
tested that hypothesis yet but from what I have garnered so far, using a
calibrated gamma of 1.8, I have a good linear relationship between the Lab
values I specify in my Photoshop documents to the Lab values that I measure
on the faceplate of the monitor with my DTP-92. AND, I suspect the same will
happen if I decide to change my calibrated gamma to 2.2. That's going to be
interesting to see.
One last tought. I would surmise, and Bruce Lindblom and the others would
correct me if I am wrong, that the choice of gamma used to be more important
in the pre-Photoshop 5.x era where digital counts were going straight to the
display. Then, I agree with the notion that 2.2 was more linearly related to
psychometrics than 1.8.
Now, if anyone has pointers or tips on how to measure gamma from a set of
measured xyY values, I would be most interested to hear about it.
--
Roger Breton
Laval (Quibec)
Canada H7A 3Z5
>
Thoughts upon monitor gamma settings. We work primarily in an rgb workflow
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within the Adobe RGB workspace. Though we're in a MAC environment we are
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using a 2.2 gamma @ 6500k. This seems to work fairly well with most images.
>
We output to rgb printers and film recorders 95% of the time. Does any one
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know of any technical reasons which would warrant the 1.8 gamma (MAC
>
standard) or different white point temp?
>
>
Rich