I am trying to find a VERY good Telephoto lens. I need a very good zoom. I have two lenses now for my camera, a 28-70 and a 70-300 but I need something more. I am trying to get more into Nature photography and sometimes just cannot get close enough to my subjects. I have seen lenses that are supposed to be 500-1000mm(1000mm with 2x lens attachment - 500mm without) but it is only about $150 and that just seems awfully cheap to us. It is a Opteka 500mm f8.0 Telephoto Lens. I do not know if this is a good lens or not. If there is a better one, can someone direct me in the right direction? THANK YOU!!!!

I have seen a few people using that said lens and they produce poor quality images. They use them for ID proof images only. They(if I am correct) are a manual preset diaphram lens that doesn't meter well and no AF . I personally think you'd do better cropping a 70-300 image... even if it was film ;)

A 500mm mirror lens is an OK start to get into nature imagery, but I would suggest finding a sigma/tokina 400mm prime(used even) or a 170-500/50-500 sigma.

Thank you! I really appreciate the help, and that was actually the answer I have gotten other places as well...... THANK YOU!!!

The Tokina 400mm f5.6 is a really good bargain. It's not made anymore but you can usually find them at KEH.com or Ebay. I didn't have a problem using it with my Fuji S2, but have heard that they don't autofocus with every newer camera. Tokina might be able to give you more specifics. I've also used the Nikon 80-400 VR lens and it's very good as well (quite a price difference though).

Well you could get a 2X AF teleconverter.

Well if you got the TC route, don't bother getting a AF TC because your lens will become a 140-600 F7.1-F11 manual focus lens ;) While that may sound OK, try to manually focus your 70-300 first, then stop down to F11(DOF preview) and see what your view will be ;) Do you think , with the darkness F11 will give you, that you can manually focus on non static subjects?

Sort of depends on what you want to do. You need 400mm (and preferably 500mm) for birds and wildlife IMHO. I've owned the Tokina 400mm mentioned and thought it was very good. It sells for something like $250 used.

At one time, I also used the Nikon 300mm f/4, which had better optics, but was too short. It sells for soemthing like $450/$500 used if I'm not mistake and $1000 or so new with AF-S. I also used a 1.4x Tamron SP Teleconverter with the Nikon for an equivalent of 420mm and f/5.6. AF was a little slow.

I use a Sigma 50-500mm now, which was about $850 new. It is probably a little optically inferior to the above two choices and slower f/6.3 at the long end, but I get better wildlife pictures beacuse of the reach. The HSM focusing motor isn't bad. I've found that you really need a monopod with this lens for best results. You can't use it with a TC and get anything usable.

I had the use of the Sigma 170-500mm for a while and it seemed inferior to the 50-500 to me, but still a good lens. It runs something like $500 new.

I also have the Nikon 70-200, which is better optically than anything I've listed, focuses fast, and has VR. But it's too short for many applications and too expensive for what you get ($1,600 new), but the fast f/2.8 aperture is really nice. I might go for one of the older Nikon 80-200mm 2.8s for something like $450/$500 used.