i use this lens quite often...
you don't have to use the conversion mode. it is hasslesome.
just screw on the lens with the 52-58 step-up ring (provided in the
A model), and put the camera in macro mode. this should enable the
camera to focus properly.
however, the auto-focus sometimes has difficulty focusing in flat
conditions. i've found that adjusting it to 0.11m in manual focus
mode works well.
also, when possible, use a smaller aperature like f4.0 so the edges
of the image remain sharp. at f2.0, the edges of the lens come
into play, and really softens/blurs the periphery of the image.
if using other filters in-between the wide angle, you might have to
zoom in a little so there is no vignetting.
overall, out of all my filters & add on lenses, this one gives me
the most reward. i enjoy the wide-angle perspectives, and am
always looking for opportunities to exploit it.
--
-jason
http://www.pbase.com/perpetu8/portfolios