RE: filmscanners: LED Illumination for Film Scanners

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

> Austin Franklin wrote:
> >
> > > A couple of years ago someone on the darkroom newsgroup was
> working on an
> > > LED light source for enlarger heads, utilizing clusters of
> high-intensity
> > > LED's. I don't know what happened to the project, but at the
> time a lot of
> > > people were really excited about the technology and the
> initial results
> > > showed a lot of promise.
> > >
> > > http://www.trailing-edge.com/www/led.html
> >
> > Yes, and look at how uneven the lighting is.  For an enlarger,
> that may turn
> > out to be a very bad idea, simply because you can't adjust each
> individual
> > LED for even illumination.  At least with a CCD, you can adjust
> the gain for
> > each sensor element to get even illumination.
>
>       All that you would need to do is shoot this array through
> some sort of
> diffusing device.

And that was the question, was there a diffuser of some sort, and that has
gone unanswered.

> After all, light bulbs aren't exactly evenly
> illuminated and those have been used for years in enlargers...

Yes, and incandescent light bulbs used in an enlarger get a condenser
system, which is entirely different than a cold light head, which is
basically what most scanners use for illumination.