If you are looking for a budget longer lens in the 70-300 range go with Nikons version with vibration reduction (I think they may have two versions). I think it retails for around $550 new ( I have one I picked up in 2007 laying around somewhere). For the price its a decent lens, altho can be a little soft at the long end (Im very picky), but most likely better than the Sigma. Its a f4.5-5.6 so its not a fast lens. Stopping down to F8 at the long end will help with sharpness
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