ingo wrote:
>
>  If the above is not terebly wrong, it seems to me that what you are
> doing is adjusting the contrast range of the mid tones only, as there
> is no information about the higjlights in the file.

All the data is non clipped. By scaling light source and ambient
source intensities I can make sure the scene fits in 0-1 range.

A scene developed normally in povray where sun shines into a room
without light sources the lit area might have 500% intensity and
get clipped when the rest of the room seems to be lit enough. I then
scale all sources by 0.2 so I get all the data. That is why 16 bits
per channel are needed.

> Now we over expose to make shure that we get all the details in
> the shadow. If we develop this film normaly, the resulting negative is
> not usable, it has a too high density and contrast to print. So we
> develop shorter.

> In a
> low-contrast scene the opposite is done, under-expose, over-develop.


out ^          __
    |      _--*
    |    _/
    |   /
    |  /
    | /
    |/
    +------------> in
    
So developing stretches the scene's intensity range down along the
curve. Exposing stretches the range up along the curve. I just looked
at linearised film response curve and concluded that it's just a typical
compress operation. Check: density=blackness ? :)


_____________
Kari Kivisalo

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