Docs: Cineon Settings white point converts exactly only without Highlight Rolloff

The footage page said the 10 Bit White Point becomes the Converted White
Point. That holds with Highlight Rolloff at 0; at the default 20 the top of
the converted range is bent into a curve, as in the Cineon Converter effect,
and the white point converts to a lower level.

docs/footage.md

@@ -94,7 +94,7 @@ used, and layers that ran to the end of the footage keep doing so.
 | Fields, pixel aspect, loop | As in After Effects. |
 | **Assign Profile**, **Interpret As Linear Light** | The colour profile the file's values are in (the working space converts from it), and whether they are linear light. |
 | **Preserve RGB** | The file's values enter the composition unconverted: no colour profile, linear light or working-space conversion, and float files (OpenEXR, float TIFF) keep their linear values instead of being sRGB-encoded. Use it to convert chosen layers yourself with an OCIO effect, or to read data passes (depth, mist, normals) as numbers. |
-| **Cineon Settings** (DPX and Cineon files) | With *Logarithmic Conversion* on, the file's log code values are converted to the *Current Gamma* (1.7 by default; 1 gives linear light): the *10 Bit Black Point* (95) becomes the *Converted Black Point* (0), and the *10 Bit White Point* (685) becomes the *Converted White Point* (1023). *Highlight Rolloff* (20) rolls values near and above the white point off gradually; at 0, a 32 bpc project keeps over-range values. *Units* shows the converted points as 10-bit, 8-bit or float values. With Logarithmic Conversion off (the default), the code values are shown as stored. |
+| **Cineon Settings** (DPX and Cineon files) | With *Logarithmic Conversion* on, the file's log code values are converted to the *Current Gamma* (1.7 by default; 1 gives linear light): the *10 Bit Black Point* (95) becomes the *Converted Black Point* (0), and with *Highlight Rolloff* at 0 the *10 Bit White Point* (685) becomes the *Converted White Point* (1023). *Highlight Rolloff* (20) bends the top 20% of the converted range into a curve, as the Cineon Converter effect does: the white point then converts to a level below the Converted White Point, and brighter code values stay below it. At 0, a 32 bpc project keeps over-range values. *Units* shows the converted points as 10-bit, 8-bit or float values. With Logarithmic Conversion off (the default), the code values are shown as stored. |
 
 Settings ▸ Import ▸ **Report Missing Frames** (on by default) lists the missing frame numbers
 when a sequence imports; Interpret Footage lists them too.