In article <4qrif5$d9i@usenet.ucs.indiana.edu>, smitra@gibbs.physics.indiana.edu says...

>Why don't still photographers use wide-angle converters as often
>as teleconverters? I mean, folks rush to buy 1.4x or 2x
>teleconverters, giving up precious f-stops and rendering their
>zoom lenses at the long (f/5.6) end virtually useless by halving
>the effective aperture diameters, but they are wary of, say,
>a .42x wide-angle converter. Video photographers/cinematographers
>do. Why not folks here?

Because, virtually all are T E R R I B L E ! ! ! when used on 35mm
camera lenses, even at minimum aperture. Only one of the several
that I have tried was good for 35mm (at f22, mounted on a 28mm lens
to make a full-circle fisheye of about 160 degrees). I use them on
Hi-8 video cameras, and the performance, even in low-light, varies
from good to excellent (the above-mentioned converter) - I don't
know why they work so much better on video cameras, though.
BTW, some 35mm lenses with good 1.4X converters attached can be
very sharp, and a few lenses are quite good with 2X converters
attached, which is why I own 5 different Nikkor rear converters...
(and four WA front converters for the Hi-8 camera...).
Hope This Helps