Lens Upgrade - Nikon

im looking to upgrade from my 80-200mm f2.8 to something with a longer reach i was looking at the sigma 50-500mm or the nikon 300mmf4 and suggestions? i would be using this for sports so i dont know if i should just save my money and get a faster lens

I know the Nikon 300 f4 lenses are incredibly sharp. The older AF version (not the current AF-S) wasn't really quick with autofocus, but the AF-S version is supposed to be much better in this regard. Not being a sports shooter or having first-hand knowledge on this, I can't really help much - but you might try asking in the Sports forum on this site too. I haven't been very impressed with long tele zooms that cover a huge focal length range.

I have been thinking about the Sigma 50-500 myself and a friend of mine who is a pro highly recommends it. If I remember correctly its significantly cheaper than the Nikon 300.

AV, do you think the quality would improve if you went for a tele with a smaller range like the sigma 150-500 ?

Focal length range itself really is more of a symptom than a problem - for example Nikon's 80-400 is very sharp but most I've used (although that isn't many) haven't been anything I've wanted to buy. The Nikon 80-400 is expensive, big and focuses slow - along with variable aperture and their first attempt at VR... So I'd have a hard time really recommending it unless it's updated.

Tokina's older 400 f5.6 is a really good buy but I've heard about a problem with compatibility with newer cameras. Can't recall it being quick to focus, but not usually something that's important to me. The Nikon 300 f4.5 ED manual focus I had was one of the sharpest lenses I've owned. I'm not a "primes are always sharper" guy, but in longer lenses this has usually been my (fairly limited) experience. I've heard and read (but no personal experience) that Nikon's 300 f4 AF-S and their 1.4x TC is a really good combination.

PS - Martin, I like your signature.

How fast of a lens you buy is determined by the lightening during the sporting event. If all the events you shoot your not using the full aperture of F2.8 then you may be able to get a slower lens but if you are shooting below F5 most of the time then you will need faster glass or not as long of a lens (to keep the F stop within the usable range) to be able to stop the action.

Thanks for the info there AV and the comment on my signature too. Actually its a quote by Catlin Matthews that fits well with me. I have always felt a need to get out alone in the forest at least a couple of times a week and discovering photography gave me a really good reason to do this. Now people think I'm dedicated to my art when I spend the morning in the jungle up to my neck in mosquitoes and leaches rather than just thinking I'm weird.