M> Cannot be used on LX with rear filters (but I don't think that's neccessary).
I will try to get a definite answer from my friend who got several of
these in Moscow and who is fairly proficient in RF/U/CIS photographic
equipment, as soon as he returns from there though...
Personally, I would think that the rear filters are almost surely part
of the optical design, and should be there at all times. It's, I
think, the more probable option (considering that most lenses that use
rear or middle filters require them in place, and provice a
clear-glass filter when one doesn't want to use a colour filter.
This could make a big difference in sharpness and another one in the
colour fringing.
Good light!
fra
