--- ray/doc/man/man1/rcontrib.1	2012/06/14 22:49:34	1.4
+++ ray/doc/man/man1/rcontrib.1	2012/11/15 19:41:03	1.6
@@ -1,4 +1,4 @@
-.\" RCSid "$Id: rcontrib.1,v 1.4 2012/06/14 22:49:34 greg Exp $"
+.\" RCSid "$Id: rcontrib.1,v 1.6 2012/11/15 19:41:03 greg Exp $"
 .TH RCONTRIB 1 5/25/05 RADIANCE
 .SH NAME
 rcontrib - compute contribution coefficients in a RADIANCE scene
@@ -101,9 +101,9 @@ The
 option tells
 .I rcontrib
 how many rays to accumulate for each record.
-The default value is 1, meaning a full record will be produced for
+The default value is one, meaning a full record will be produced for
 each input ray.
-For values greater than 1, contributions will be averaged together
+For values greater than one, contributions will be averaged together
 over the given number of input rays.
 If set to zero, only a single record will be produced at the very
 end, corresponding to the sum of all rays given on the input
@@ -113,8 +113,9 @@ This is equivalent to passing all the output records t
 to sum RGB values together, but is much more efficient.
 Using this option, it is possible to reverse sampling, sending rays from
 a parallel source such as the sun to a diffuse surface, for example.
-Note that output flushing via zero-direction rays is disabled
-for accumulated evaluations.
+Note that output flushing via zero-direction rays is disabled with
+.I \-c
+set to zero.
 .PP
 The output of
 .I rcontrib
@@ -158,7 +159,7 @@ this will be applied to a "%d" format in the output fi
 specification if present.
 The actual bin number is computed at run time based on ray direction
 and surface intersection, as described below.
-If the number of bins is known in advance, it should be specified with the
+The number of bins must be specified in advance with the
 .I \-bn
 option, and this is critical for output files containing multiple values
 per record.
@@ -168,9 +169,9 @@ it has been defined via a previous
 or
 .I \-e
 option.
-Since bin numbers start from 0, the bin count is always equal to
-the last bin plus 1.
-Set the this value to 0 if the bin count is unknown (the default).
+Since bin numbers start from zero, the bin count is always equal to
+the last bin plus one.
+Set the this value to zero if the bin count is unknown (the default).
 The most recent
 .I \-b,
 .I \-bn
@@ -185,7 +186,7 @@ and
 .I \-y
 if the
 .I \-c
-is 0, when they control the resolution string
+is zero, when they control the resolution string
 produced in the corresponding output.
 .PP
 If a