CV 15mm uv/ir filter

[ron klein]

Which size uv/ir filter should be used on the CV 15mm?

[daveco]

39mm, with Milich adapter.

[projectbluebird]

Cosina makes a 77mm filter adapter for the 12mm, that (apparently) can be made to work on the 15. The huge angle of view on these lenses makes filters difficult, though on the M8 that might be less of a problem.

[jaapv]

39 mm. Mount reversed, and wedge with a piece of rubber band or whatever. A filter only makes sense if you code the lens as a WATE, and even then, if there is a lot of IR around you may see cyan vignetting. Cornerfix may be the better way to go.

[Ben Z]

How to add female 39mm threads to the CV 15 to take a 39mm IR filter:

1. Remove glass from any B+W 39mm filter (B+W filters are brass, which the threads don't bind with another filter as easily as aluminum).

2. Grind down the male threads flush with the landing.

3. Use a little 5-minute epoxy to glue it to the front ring of the lens, just inside the fins (hood petals?).

4. UV/IR filter can now be attached in the normal manner, won't fall off, and will come off easily whenever you want, like any normal lens, and the adaptor will not vignette on film. If you use a Leica-branded IR filter, don't screw it really tight because Leica filters are aluminum and they do tend to bind on.

[jaapv]

That, Benson, is brilliant. I will do so.

[baycrest]

I just put some "black silicon" (you know the stuff you use to put a seal on around your bathroom fixtures) on the "39" filter threads and placed it on the lens, waited 10 minutes and its dry. Its not coming off anytime soon.

Best
Rob