Re: LEDs for Focault Testers
Bob Madden (madden@netcom.com)
Wed, 19 Apr 1995 15:49:40 -0700 (PDT)
Ron, there doesn't seem to be any advantage of one over the other. It is
just that you have to find a way to have a frosted surface in front of a
Halogen (Mag-Light) type bulb. The Green LEDs come frosted and cost less,
if cost matters. Both work equally well. The first I made was with a
Halogen bulb and the light went through a small prisim that the surfaces
I difussed with 600 grit. With the Green LED I didn't use the prisim. I
like the Green light because I think I see better using it. But that doesn't
mean I really do.
):-{])) <---- madden@netcom.com
madden@svpal.org
Remember amateur astronomers:
"keep looking for the next Universe"
On Wed, 19 Apr 1995, Rob O'Toole wrote:
> I've noticed that several people recommend using LEDs (green) for their
> light source in a Focault tester over a bulb. What is its advantage over
> a small bulb? Why use an LED? Thanks for your patience.
>
> -- Rob O.
>
>