--- ray/doc/man/man1/rad.1	2015/05/26 10:00:46	1.11
+++ ray/doc/man/man1/rad.1	2021/01/01 19:14:43	1.12
@@ -1,4 +1,4 @@
-.\" RCSid "$Id: rad.1,v 1.11 2015/05/26 10:00:46 greg Exp $"
+.\" RCSid "$Id: rad.1,v 1.12 2021/01/01 19:14:43 greg Exp $"
 .TH RAD 1 2/1/99 RADIANCE
 .SH NAME
 rad - render a RADIANCE scene
@@ -444,7 +444,8 @@ This variable designates a global photon map to be gen
 .I mkpmap(1)
 and used to accelerate rendering.
 The file name must be followed by the number of photons to be stored
-in the map, and this number may be followed by a bandwidth for rendering.
+in the map, and this number may be followed by a bandwidth for rendering,
+which can be two arguments if bias compensation is desired.
 There is no default value, meaning that a global photon map will not
 normally be created.
 .TP
@@ -454,7 +455,8 @@ This variable designates a caustic photon map to be ge
 and used during renderings to model light transmission by reflecting
 and refracting surfaces.
 The file name must be followed by the number of photons to be stored
-in the map, and this number may be followed by a bandwidth for rendering.
+in the map, and this number may be followed by a bandwidth for rendering,
+which can be two arguments if bias compensation is desired.
 There is no default value, meaning that a caustic photon map will not
 normally be created.
 .TP