Dave Brooks, in a post that I never received but which I saw in the archives, was chatting about fisheyes in general, the Zenitar 2.8 16mm in particular, and filters.
My Zenitar has a sort of filter ring, that's cut away on the sides, so there's only threading at the top and bottom of the from element. Presumable, the cutaways are to prevent vignetting. How easily one could install a filter with such an arrangement is likely another story. Certainly, any filter, no matter how slim, would vignette, but if you plan on using it on your *istD, that may not be an issue. The lens came with four tiny filters that screw on the back, green, red, and two clearish ones (UV and haze?). I have no idea if the red is #25, but comparing it to the much larger #25 that I have, I'd say "no". Whether you can get #25 filters of that size to screw onto the back of them, I don't know, as I have no idea if that's a standard size filter or not. Next time we do a TOPDML, I'll have it with me, and you can take a look. BTW thanks for your comments on my photo. Glad you liked. cheers, frank -- "Sharpness is a bourgeois concept." -Henri Cartier-Bresson
