07-29-2011, 01:34 PM
Thanks everyone for being kind enough to post here
Though the Sigma 150-500 is an HSM lens, there is not much of a confirmation how good the auto focus is, is it fast enough to track a flying bird? I have also read that the sharpness of the lens at 500mm end is sharper than that of 150-500...so things are pretty confusing to me. What about the CA? I am yet to find any comprehensive test report on CA factor of both these lenses at the extreme end. I am more tempted towards sharpness and contrast, both seems to be better at the extreme for Tamron. One more thing that strikes me is, without a Motor Tamron costs almost the same as Sigma which features both OS and HSM. If price dictates quality (considering both have almost the same Brand Value as Third party lens manufacturer), then Tamron should give better IQ.
At the end I am still very much confused... <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='
' />
Though the Sigma 150-500 is an HSM lens, there is not much of a confirmation how good the auto focus is, is it fast enough to track a flying bird? I have also read that the sharpness of the lens at 500mm end is sharper than that of 150-500...so things are pretty confusing to me. What about the CA? I am yet to find any comprehensive test report on CA factor of both these lenses at the extreme end. I am more tempted towards sharpness and contrast, both seems to be better at the extreme for Tamron. One more thing that strikes me is, without a Motor Tamron costs almost the same as Sigma which features both OS and HSM. If price dictates quality (considering both have almost the same Brand Value as Third party lens manufacturer), then Tamron should give better IQ.
At the end I am still very much confused... <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='
' />