Op 18-5-2021 om 12:52 schreef Dave Blandston:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> I think there are two tracks here to consider: (1) the use of 'pitch
>> black' in pigments and textures, where the use of 1/256 or 1/257 would
>> be the way to go; (2) the use of <0,0,0> in a 'geometrical' construction
>> like a height_field or, I suppose, an isosurface or a parametric object
>> or whatever, where 'true' zero would be a must. this should be clear
>> from the onset in any scene. Height_fields in particular certainly make
>> good use of 'true' zero. Approximations should be reserved for
>> pigments/textures.
> 
> If I may offer a humble opinion/observation, using a value of 1/256 for the
> purpose of multiplying the brightness of an object does not make sense (to me,
> anyway) for this reason: Assuming the base scene is lit such that a fully-lit
> part of an object will have the same approximate output RGB value as the
> corresponding RGB value of the input pigment, a value of 1/256 will result in a
> pixel value of 0. In my opinion, that should be considered the true base value.
> What is the alternative? 1/256 is arbitrary. Why not 1/317? It's not possible to
> foresee what value is actually going to be desired.
> 
> Also, even the best monitors don't display pure black anyway. Maybe future
> technological developments will change that...
> 
> Kind regards,
> Dave Blandston
> Suggested motto: "With POV-Ray anything is possible, but nothing is easy"
> 

Well, personally I am no expert on the question, and I prefer to let 
others answer/discuss this point. Who's next? :-)

-- 
Thomas

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