P3D Re: Viewers and white LEDs

[Greg Erker <erker@xxxxxxxxxxxxxx>]

>My recommendation for comparing LEDs is to choose a single viewing angle
>that is common like 20 degrees and order from various vendors. Then you
>stand a chance of comparing them. I suspect that the best one will
>indicate the manufacturer that has the most control over the process.
>Then choose whichever of their LEDs is most useful for your application.

  Sounds like a good plan.

  If you go with condensor lenses then
I guess they need to be equal in diameter
to the size of the film. This isn't too
bad for 5 perf Realist images but would
make for a big light box for a medium
format viewer (70-some mm diagonal).

  BTW Edmund Scientific sells holgraphic
diffusers in 25 and 50mm diameter. They
have 10, 15, 20, 25, 30, 40, 60 and 80
degree diffusing angles available.
Unfortunately they are $90 and $130 a
piece (25, 50mm). Part Number J54-492
to -507.

Greg E.