Have both M* and M400/5.6, added katzeye split-prism and as Albert says there
are issues with spot metering, Thats a personal choice for you baig,
for myself, use both those len's for birding quite a bit, when subject is static, benefits of
split-prism outweighed the issues of spot-metering. A bird in flight on the other hand,
one might be better off with a matte screen, what Albert mentions sounds very
interesting indeed,in addition, seems to me a matte screen has an advantage over
a split-prism when shooting macro. In thinking about your K135/2.5, assume that would be your go-to lens for portraits&people, if it was my situation, would go with the matte and something like a viewfinder magnifier for that particular application.
Its my opinion, in portraiture, if using split-prism, because of critical nature of subject
something along the line of hand held spot or incident meter required.
Last edited by BillM; 01-13-2011 at 09:38 PM.