P3D Re: Mirror Lenses

[Steve Berezin <Sbere@xxxxxxxxxxxxx>]

Lawrence A. Haines wrote:

> Does anyone have experience with long focal length lenses that use
> mirrors ratherthan solid glass?  I notice 500 mm mirror lenses costing
> about $100 each being sold new.  They are lighter and smaller in
> diameter and in those regards would be very good for paired lens
> stereo.  Offhand it would seem that the reflected light of the mirror
> might reduce the available light, but I really do not know.

I don't know if this is relevant but I have a slide viewer made by the David
White (realist) company which uses a long focal length partial mirror to
view slides.  It is called a "Realorama".  I found that it is relatively
ineffective because it is difficult to get enough light to view the slides
easily.  It is a steal-the-light viewer but it may be more effective if
artificial light is added. Also the resolution just was not very good due to
the grainy nature of the light disperser.

> Some of  the
> store people I have talked to say they are not as sharp as regular glass
> lenses, and yet there are those who say that if the lens is used at f 8
> - 22, they are just as sharp as glass lenses used at the same openings.
> I am interested in the experience of anyone who has used them.
>
> Larry Haines
> P.O. Box 1177
> Eastsound, WA 98245
> tel 1-360-376-4704
> e-mail <lhaines@xxxxxxxxxxxxxx>



--
Steve Berezin
sbere@xxxxxxxxxxxxx



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