--- ray/src/rt/rayinit.cal	1992/03/03 13:58:11	2.3
+++ ray/src/rt/rayinit.cal	1992/10/21 11:20:26	2.5
@@ -96,11 +96,11 @@ noneg(v) = if(v,v,0);
 red(r,g,b) = if(r,r,0);
 green(r,g,b) = if(g,g,0);
 blue(r,g,b) = if(b,b,0);
-grey(r,g,b) = .3*r + .59*g + .11*b;
+grey(r,g,b) = noneg(.263*r + .655*g + .082*b);
 clip_r(r,g,b) = bound(0,r,1);
 clip_g(r,g,b) = bound(0,g,1);
 clip_b(r,g,b) = bound(0,b,1);
-clipgrey(r,g,b) = bound(0,grey(r,g,b),1);
+clipgrey(r,g,b) = min(grey(r,g,b),1);
 
 dot(v1,v2) : v1(1)*v2(1) + v1(2)*v2(2) + v1(3)*v2(3);
 cross(i,v1,v2) : select(i,	v1(2)*v2(3) - v1(3)*v2(2),