RE: filmscanners: LED Illumination for Film Scanners

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

> I am another engineer(!) (not that this is relevant to reading a
> manufacturer's spec) and LEDs don't have MTBFs of 1000 hours!

The one catalog I pulled off my shelf gave that figure.  It seemed
inordinately low to me, but it certainly was 1000.

> the
> consistency of light i.e. unchanging spectral characteristics.

That has nothing to do with even illumination, which is different than
consistent illumination.

> In fact
> the MTBF of ordinary boring nothing special LEDs is around 100x  your
> stated figure

Whose did you find had that?  Lumex stated 10,000 hours, which is 10x the
original source I quoted.

> "If packaged properly, LEDs emit light for a much longer time period than
> almost every other alternative light source technology. ... The mean time
> between failure (MTBF) of high quality LEDs properly packaged, is on the
> order of millions of hours. "

We don't know what LEDs the Nikon scanner uses, nor will we unless someone
either takes their scanner apart, or buys a spare LED array.  The original
point was that they do have a life span, as anything does.  The claim was
that the LEDs in the Nikon are "permanent", and I do not believe they are.
They may be for some people's use, but for others, it will be an item that
they will probably have to replace over the usable life of the scanner.