P3D Re: 82mm stereo polarizer

[Bill Davis <bd3d@xxxxxxxxxxxxx>]

>>I thought the tip of using a single, 82mm polarizer (or any kind of)
>>filter was ingenious. But, I heald a ruler at 82mm across my Sputnik
>>lens (which are shorter interoculer distance than a Realist) and I
>>still don't know how you'd avoid some vigenetting - esp. if the filters
>>rim was wide.
>
>I see there is an even wider filter listed at 90+ mm (forget the 
>exact size.  Would the larger one be better?  Please advise because
>these filters are not exactly cheap! :-)
>

Exactly.  I, however *am* cheap, so if these things were more than ten or
twenty bucks each it would be too much for me.  

I showed a polarizer unit for a Kodak at NSA Richmond.  This would work on
a Sputnik, and a Realist, too, if you snap off that lens cover/baseball
visor thing.  

Basically consists of a a 110 mm disk cut from a sheet of polarizer from
Edmunds (8.5x19.5 inch @ $20.00).  This is attached to an L-shaped bracket
and anchored to the tripod socket. To rotate the sheet, I used the top 10
mm of a plastic film can.  Then carved the center material from the cap,
leaving just the outer snap ring part.  This is cemented to the center of
the disk, rim of can is cemented to bracket.  When cap is snapped on to
rim, opening is centered over viewfinder, allowing preview.  

The polarizer rotates 360 deg. about the center, unlike the Rochwite's
limited 90 deg.

Total cost maybe 5 bucks worth of materials. Cheaper than taking your wife
along to hold the filters.

Any questions? 

I'll be showing this and a bunch more at our as-yet unnamed stereo club at
the December 14 "Do-It-Yourself" night.


Best regards,
Bill Davis

mailto:bd3d@xxxxxxxxxxxxx



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