I am looking for / needing a zoom to 300mm. Can be Canon or other brand. I currently have a Cosina 28mm-210mm but it is not very sharp at either end. So sharpness is a must and $$ are limited as well. Any suggestions based your experience. I would even go for a 300mm prime but have found anything in any type of reasonable price range. Many thanks.
Actually, now a days you can find some pretty good deals on the manual focus Canon 300 f/2.8 primes on ebay, I have seen some great deals less than a grand, another option is to get a hold of the Tamron adaptall 300mm f/2.8, I sold mine a few months ago for $500 with both teleconvertors and a mount for a Canon FD, so for big glass, there are some good buys around now a days.
Good point, what are you looking for, picturetaker? FD mount or EOS mount?
On the EOS side, I've been looking at the 70-200 f/4 L. Compared to the f/2.8 and the various IS models, it is cheap. (Well, relatively, that is... It offers good value for money!) And it can be used with the 1.4x and (less ideally, with limitations) the 2x teleconverter.
Other brands with EOS mount? I have briefly looked at Sigma and Tamron, but I can't suggest anything there. (Not because it's not there -- I just didn't look very long.)
Canons Standard consumer 75-300 is quite a nice lens and when I worked in the photo shop they were less than $200 pretty good qualtly lens, with metal mount and such. You might check with a local photo shop to see what they might have in stock.
I have a EF100-300 USM.
It's a very good lens for the price (£200).
It's pretty sharp, the AF is very fast, and it's fairly light as well.
Previous to the Canon, I had a Sigma 70-300 APO, which was optically, a great lens, but the major downside was the front element that rotated on focusing - not good with a polariser. Unfortunately, I dropped that lens, and it was destroyed. (and not insured )
Try the Tamron AF 70-300mm f/4-5.6. I have it in Pentax mount, but it is also available for Canon SLRs. It's a good lens, especially for the price (less than $200 new), versatile and sharp throughout the whole range. The only drawback is little bit of chromatic aberration, but visible only when shooting against the light or when there are strong specular reflections in the field.
If you really want a nice 300 and a new EF-mount lens is out of the budget, it could be worth purchasing an FD mount camera and dedicating it to FD lenses that you can't afford in EF-mount. I have an FD 300/4L, and it's a fantastic lens and isn't super expensive.
I've gone to the occasional birding workshop, and there are all these guys with their new autofocus lenses, but they usually can't afford anything longer than 400mm--well maybe that's okay for one of those APS-C format digital cameras--but I'm happily using my manual FD 600/4.5 (around $1200 in mint condition), which in that situation is going to get better results.