In article <51its8$m3o@nntp1.best.com>, Robyn@scratchpad.com says...

>This is probably a dumb question, but is there a real difference in
>qualilty between fixed focal length lenses an zoom lenses? Are there
>any other advantages to using a fixed focal length as opposed to a
>zoom?

Few questions are dumb - but the answers you get may be....;-)
GENERALLY, zooms are lower in optical quality than primes (lower
resolution and contrast, particularly at frame edges and corners,
at some focus distances, and at wider apertures; less even
illumination of the frame; greater linear distortion; greater
tendency to flare; more likely to have alignment problems causing
greater quality variations among samples), have smaller maximum
apertures than primes (limiting the light levels you can shoot
under without flash), are larger than (single) primes, are harder
to focus than primes (both because of smaller maximum apertures,
and because most zooms focus by changing focal-length which can
cause confusing image magnification changes as you focus), and
are often variable-aperture types (making manual exposure more
awkward, and the lens even slower where you need speed the
most - at the long end of its zoom range). But there are a few
really good zooms, or ones that are so useful that one is willing
to overlook a few minor shortcomings. I have reduced a large zoom
collection down to a few (I find the tele range the most useful
for zooms, with moderately-wide-to-short-tele zooms useful when
time and simplicity are primary concerns), and have added compact
and slower versions of primes to my set of fast primes for those
situations where weight and size are more important than lens speed.
You might consider, as an alternative to zooms, a good 28mm f2.8,
50mm f1.8 (or so), and 105mm f2.8 (or so); or a 35mm f2 and 85mm f2
(or so) - or skip the 85-105, and add a fast 70-210 or 80-200.
Hope This Helps