RE: filmscanners: LED Illumination for Film Scanners

["Austin Franklin" <darkroom@ix.netcom.com>]

> Moreno wrote:
> >And taking things one step further, a dense LED array positioned
> closer to
> >the negative could even be
> programmed to provide some degree of selective dodging/burning/variable
> constrast control. With an appropriate control mechanism, a user could
> adjust for dead even lighting across the easel for a specific lens/format
> size combination.
>
> This is a very signifficant "AhHa!" IME. I'm actually surprised that no
> programs, to date, are using that possibility. As I might have
> said sometime
> ago, we users *do* have some ideas worth considering, from  time to time.
> ;-)

If you could make it very very dense and were able to calibrate it somehow
(which is an big task in and of it self to calibrate a 2d area this size
with sufficient resolution), possibly, but I believe it won't work very well
in a real implementation.  You have to diffuse the LEDs in order to make
them illuminate evenly, but in doing so, individual LED coverage will
overlap substantially, as well as their area of coverage becoming larger.
This means your area of control becomes much smaller.