Re: Flat Black - where, what ??

Bill Greer wrote:
In many if not most places (in a telescope) glossy black can be
substituted for flat black with superior overall results

Pete wrote:
now that is a novel principle - care to explain?

I'm not Bill, but I'm guessing it's because glossy black reflects little
light (because it's black), and what it does reflect, goes in a very
particular direction, which most of the time is not toward the eyepiece.
Whereas with flat black, which reflects diffusely, light hitting any
place in the tube has some chance of making it into the eyepiece.

It's like if you look at a streetlight in a mirror. Most of the mirror
is not reflecting any light into your eye; it's only the small part of
the mirror where you see the streetlight's image that is directing any
of that light toward you. Whereas if a cement sidewalk is the thing
that's reflecting the light, any individual part of the sidewalk is
less bright than the one part of the mirror, but all parts of the
sidewalk reflect *some* light toward you.

--
Brian Tung <brian@xxxxxxx>
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