sony a200

[2e1var]

Best and cheapest, that's a bit hard to do !
I bought an a230 last year and have has some good results with Sony's 75-300. Works well for anything on the ground and you can get some nice shots of stuff in the air if the light is good, struggle to get anything crisp if its dull though. That's my experience but you can probably go Tamron/Sigma for less and get good results or even second hand.

[POL]

I would agree with the above, I have an A200 and the Sony 75-300, shots are available on my website and on Flickr...

Tamron will probably be your best bet, if you go for a Sigma, make sure it's a DG HSM version.

[2e1var]

I'm considering an upgrade myself to a 75300G but can't quite convince myself to splash the cash ! I read on another forum that the best to go for are as follows (in order of price)

Minolta 70-210 f/4 "Beercan" (can only be found used)
Minolta 75-300 f/4-5.6 "Big Beercan" (only found used, both of these are old style metal bodied lenses and look quite similar to each other)
Minolta 100-300 APO (APO version is important)
Tamron 70-300 USD (the new one)
Sony 70-300 G
Sigma 50-500
Sony 70-400 G

It would appear the Minoltas can be picked up for quite reasonable money on ebay. Does anyone have any experience, would the quality be significantly better than my boggo 75300 or anything approaching the G ?

[2e1var]

Was just searching for some info on the 70 - 300G and this thread popped up in my search from 9 years ago ! I eventually went for the Tamron 70 - 300 SP and haven't had much luck with it. I came to the conclusion that I was either a really crap photographer or the lens/camera was duff. Most flying stuff I shoot is blurred, very rarely do I get a crisp image. Anyway, last ditch attept, the 70 - 300 G now goes for about £300 second hand, it arrives Wednesday, finger crossed.