BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

Reply to thread

Message: <blockquote data-quote="Jaff" data-source="post: 1713863" data-attributes="member: 42340">The Tamron 70-200mm f2.8 on the other hand is a much better lens optically to the Sigma but slightly suspect in terms of AF speed and accuracy. DPreview looked at all the 70-200mm f2.8's not so long ago (the MkI versions that is). When you're talking the prices the Sigma and Tamron sell for compared to the Canon/Nikon's then you've got to accept some compromises here and there. Ditto for most cut-price f2.8's, it's just something about large apertures (please no technical explanations of it!) that increases undesirable lens affects, be thankful for crop sensors in this respect, it's even worse on FF sensors. The more expensive lenses with better glass and more special elements do a much better job of controlling these problems and that's why we have to pay a premium for them and are truly usable wide open, used my 300mm f2.8 quite a few times like that lately.Sigma and Tamron lenses as a rule have some compromises to sell cheaper than the own brands, that's the way they are marketed and make their money but at the end of the day if you want the very best of performance you've got to buy expensive own brand lenses.Strayed a bit off topic here but hey, it's what Birdforum's famous for. :-O</blockquote>