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- Newsgroups: comp.sys.sgi.admin
- Path: sparky!uunet!spool.mu.edu!sdd.hp.com!sgiblab!sgigate!odin!blythe
- From: blythe@sgi.com (David Blythe)
- Subject: Re: What is the correct gamma value?
- Message-ID: <1992Dec31.104748.17242@odin.corp.sgi.com>
- Sender: news@odin.corp.sgi.com (Net News)
- Nntp-Posting-Host: banshee.asd.sgi.com
- Organization: Silicon Graphics, Inc., Mountain View, CA
- References: <1992Dec22.230429.19706@uc.msc.edu>
- Date: Thu, 31 Dec 1992 10:47:48 GMT
- Lines: 35
-
- In article <1992Dec22.230429.19706@uc.msc.edu> wes@msc.edu writes:
- >The man page for gamcal says:
- >
- > "Normally the gamma of the display should be set to
- > 2.4 using the program /usr/sbin/gamma."
- >
- >However, the following lines are found in /usr/lib/X11/xdm:
- >
- > Xlogin:glGammaDefault="1.7"
- > Xstartup:glGammaDefault="1.7"
- >
- >NOTE: These files (Xlogin and Xstartup) do not seem to be setting the gamma
- > anyway but that is a separate issue.
- >
- >
- >Using the gamcal program to help calibrate the gamma leads me to believe
- >that 2.4 is the "correct" value.
- >
- >I am running IRIX 4.0.5 on a 4D/35. Is there a reason for the two
- >different gamma values found on my system?
-
- the correct gamma value is theoretically a property of the monitor (CRT
- and associated electronics). gamcal will help you determine what this
- value should be. In practice asthetics, religious beliefs, the application
- itself, etc, perturb this value. I believe the two values you have seen
- reflect two different opinions of SGI engineers (I think they bracket the
- typical range of values). I believe 1.7 is the installed default regardless
- of the monitor shipped with the system.
- -db
-
- >
- >
- >===============================================================================
- >Wes Barris PH: (612) 626-8090
- >Minnesota Supercomputer Center, Inc. Email: wes@msc.edu
-