Alain wrote:
>>
> If outputing to PNG or PPM, you can set the bit-per-chanel to anything 
> from 5 to 16 (default is 8). If you use, say, 10 bits and divide all 
> your lights by 4 (or divide the diffuse and ambient values by 4), you 
> can simulate a higher dinamic range. If doing this, be sure to lower the 
> asc_bailout acordingly.

No, high dynamic range is not the same as more than 8 bits per value. 
It means the format can represent several orders of magnitude in color 
values.  With 16 bit you can represent a contrast ratio of 65535:1 
(meaning the smallest color difference that can be represented is 
1/65535 of the brightest color value in the image), a high dynamic range 
format usually handles at least a few million. You could store 
logarithmic values in an integer file format but simply scaling them 
will not help.

Christoph

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