From 3243b9f38e1e94eb26e9298d5e2d04ef28dc8677 Mon Sep 17 00:00:00 2001 From: "Richard M. Stallman" Date: Wed, 27 Feb 2002 05:29:00 +0000 Subject: [PATCH] Clarify gamma correction. --- lispref/frames.texi | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/lispref/frames.texi b/lispref/frames.texi index c75099fb82f..d36d97cd1b3 100644 --- a/lispref/frames.texi +++ b/lispref/frames.texi @@ -551,13 +551,22 @@ number you specify is whether it is greater than zero.) @item screen-gamma @cindex gamma correction -If this is a number, Emacs performs ``gamma correction'' on colors. The -value should be the screen gamma of your display, a floating point -number. Usual PC monitors have a screen gamma of 2.2, so the default is -to display for that gamma value. Specifying a smaller value results in -darker colors, which is desirable for a monitor that tends to display -colors too light. A screen gamma value of 1.5 may give good results for -LCD color displays. +If this is a number, Emacs performs ``gamma correction'' which adjusts +the brightness of all colors. The value should be the screen gamma of +your display, a floating point number. + +Usual PC monitors have a screen gamma of 2.2, so color values in +Emacs, and in X windows generally, are calibrated to display properly +on a monitor with that gamma value. If you specify 2.2 for +@code{screen-gamma}, that means no correction is needed. Other values +request correction, designed to make the corrected colors appear on +your screen they way they would have appeared without correction on an +ordinary monitor with a gamma value of 2.2. + +If your monitor displays colors too light, you should specify a +@code{screen-gamma} value smaller than 2.2. This requests correction +that makes colors darker. A screen gamma value of 1.5 may give good +results for LCD color displays. @item tool-bar-lines The number of lines to use for the toolbar. A value of @code{nil} means -- 2.39.2