i have them both now (thanks jay!) some samples for your examination, at K100D, +100 focus adjustment, no tripod, F2.0 only, PPL conversion, unscientific framing. really shitty WB, sorry should have WhiBal'd it first.
edit: redid the photos, after posting them up, i realized how crap the samples were. i set the WB and used more flash to make sure the illumination was better, you can judge the colour now. deleted the carpet test, very difficult to get a super flat depth of field.
i can barely tell the difference in terms of sharpness, but there is a slight difference in bokeh and the FA31 is 8 bladed versus the FA35's 6.
in terms of usability, FA35 wins for its smaller size, but the FA31 build quality is unrivaled. FA35 focuses very fast.
if you have the FA35 and thinking about upgrading to the FA31, don't bother unless you love the build quality or if the slight difference in bokeh is that important for you.
which one do i plan to use more? FA35, 49mm filter threads and smaller size are important to me. the FA31 isn't super big, but compared to every other Limited lens, it is a big and tall fatty.
really it's not worth doing any more tests beyond this except maybe some more thorough bokeh studies, but there's not much in it at F2 (and i'm assuming the same follows for the smaller apertures).
Last edited by k100d; 03-21-2009 at 08:54 PM.