Well, I am tempted to answer both yes and no ;-) Lars Kjellberg, who runs Photodo, cooperates with a lab that makes the MTF measurements, and they are very competent and well equiped. Still, they only measure one single specimen of each lens, so you have no idea of the variability. Also, they normally measure only at infinity. Besides, choosing between lenses by MTF only is analogous to choosing a stereo amplifier from frequency response only. Good sound, and good imaging, is much more complex than that. Also, mechanical quality and ruggedness is not commented on at all in the Photodo tests. Sigma lenses, esp the cheaper ones, are reputed to be rather fragile. I surely check Photodo if I consider a new purchase, but also some discussion forums like www.photo.net. A gold mine is http://www.photozone.de/ that runs extensive surveys with feedback from owners and users of most lenses on both optical and mechanical performance. Per söndagen den 21 juli 2002 kl 18.22 skrev kostas papakotas: > i wonder how do you feel about the PHOTODO lense > tests(http://www.photodo.com/nav/prodindex.html) > i wonder if these tests are a reliable guide to lense selection. > for example Sigma lenses (contrary to some list members' and popular > opinion, get good marks)
