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Re: Reflector measurements (long)
Ivo wrote:
This suggests me that the use of reflective flexible materials such as
Mylar and similar ones does not provide a significant gain above what one
can get with a simple white paint. They can be even worse than the white
reflector, as in my test. The reason is the difference between specular
and diffusive reflection. Unless the reflective material can be laid out
with a smoothness comparable with a true mirror, it will tend to act as
a diffusive reflector. And will most likely perform below the "perfect"
diffusive reflector, a white matte surface. Stretching this reasoning a
little, *any* shinyness in the reflective material is prone to *decrease*
the reflector effectiveness, unless it is *perfectly* smooth as a mirror.
That is, unless you can see your image clearly reflected when looking into
it.
I reply:
Mylar is a specular reflector. It is very cheap and can be easily bent
around a the inside of a shoplight reflector. If you don't glue it on and
just fasten it at the edges with that plastic extrusion stuff that is used
to bind papers together it naturally forms a parabolic shape. It won't span
a very great width though as it is pretty flimsy. By playing with the width
of the mylar you can get various suitable or less suitable curves. I
wouldn't lump it in with aluminum foil.
Wayne