> > I am trying to build a polariscope as show in "ABC and XYZ of Bee
> > Cluture" But I am having a hard time trying to find Polariod "J"
> > film.  Does any body know where I could get this or can i
> > substitute some other item instead?
 
If you aren''t being too fancy, polaroid sunglass lenses should
work.  They are often available in a light tint.  To find out if
they are polaroid or not, just cross two similar pairs and rotate
when shopping - at 90 degrees, they should become very dark -  or
look at wet pavement in the direction of the sun with and without
them on .  With them on the glare should disappear.
 
Alternately polaroid filters are inexpensive at any good camera shop.
 Seeing as the exact diameter should not matter to you, you might be
able to get a deal on an obsolete size.
Regards
 
Allen
 
W. Allen Dick, Beekeeper                                    VE6CFK
Rural Route One, Swalwell, Alberta  Canada  T0M 1Y0
Honey. Bees, Art, & Futures <http://www.cuug.ab.ca:8001/~dicka>