Are there really short focal length fresnels available out there? The one on my Chamonix is worthless with the 65mm lens and I would like to replace it.
I think most installed fresnels are for general purposes - not too long and not too short. Are there custom ones available?
Sam
Yes they are sort of available. You might try a 3 inch FL in 6 X 6 inch size from Edmund Industrial Optics in NJ. It is 100 grooves per inch. About $70.00 but you'll have to cut it to your screen size. I cut carefully using a table saw then bevel the edges. The focal length fresnel you select for a 65 mm lens depends in part in your viewing distance.
www.edmundoptics.com
Nate Potter, Austin TX.
Ebony makes one that's reasonable, it's a plastic fresnel with a frosted surface that faces the lens - used with a plain cover glass. If you know your glass size I'll measure and see if it will work. IIRC these are around $80.
Maxwell also makes one for about 4x the price.
Cheers, Steve
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