+| cbr | --pbratio 1.0 --ratetol 0.5 |
++--------------+-----------------------------------------------------+
+
+
+Film Grain Retention
+~~~~~~~~~~~~~~~~~~~~
+
+:option:`--tune` grain tries to improve the retention of film grain in
+the reconstructed output. It helps rate distortion optimizations select
+modes which preserve high frequency noise:
+
+ * :option:`--psy-rd` 0.5
+ * :option:`--psy-rdoq` 30
+
+.. Note::
+
+ --psy-rdoq is only effective when RDOQuant is enabled, which is at
+ RD levels 4, 5, and 6 (presets slow and below).
+
+It lowers the strength of adaptive quantization, so residual energy can
+be more evenly distributed across the (noisy) picture:
+
+ * :option:`--aq-mode` 1
+ * :option:`--aq-strength` 0.3
+
+And it similarly tunes rate control to prevent the slice QP from
+swinging too wildly from frame to frame:
+
+ * :option:`--ipratio` 1.1
+ * :option:`--pbratio` 1.1
+ * :option:`--qcomp` 0.8
+
+And lastly it reduces the strength of deblocking to prevent grain being
+blurred on block boundaries:
+
+ * :option:`--deblock` -2
+