In article , jcs5u@faraday.clas.virginia.edu says...
>I'm looking to buy a midrange telephoto lens for my Nikon F3. Without
>the funds for an 80-200 or 70-210 2.8 I'm trying to find the next best
>thing in terms of overall quality.
>My questions:
>1) Does anyone have any information about the Sigma 70-210 3.5/4.5 APO
>or the 70-300 4/5.6? Is there any loss of optical quality by getting
>the 70-300?
>2) Would the Nikor 80-200 f4 be a better choice?
>3) Finally, are there any other suggestions?

If you want high quality at a reasonable price, I would look for
a 70-210 f4 Nikon Series E or an 80-200mm f4.5 Nikkor. If you can
afford it, the 80-200mm f4 Nikkor is about as good, but the price
is up in 80-200mm f2.8 AF territory (a VERY fine lens!), unless
used. I would avoid most off-brand lenses if your primary concern
is sharpness, though a used Sigma 50-200mm f3.5-4.5, Vivitar 70-210
f3.5 or f2.8-3.5, or Tamron SP 80-200 (70-210?) f3.5-4 can be a good
value. Most off-brand 70-300's are the pits toward the long end,
so why bother?
Hope this helps.