Originally posted by srej For a K100D should I buy a SIGMA 70-300 DG or the Pentax 50-200.
With the rebate the SIGMA is only slightly cheaper.
I'd like the extra telephoto but not at the price of quality or functionality.
Thanks
SR
I have the Sigma DG APO Macro and the Pentax.
I'm not enthusiastic about the Sigma, especially beyond 200mm. Contrast goes down toward the wide end, and I never have gotten a really sharp shot on the long end either.
The Sigma has about twice the bulk of the Pentax, but of course has the macro capability (in the 200-300mm range) and extra 100mm's. It is over 10" long with hood when at 300mm and closely focused.
I have the Sigma 18-50 which is very sharp, so perhaps there is something to the hit-and-miss aspect of Sigma lens - though the 70-300 was $219 and the 18-50 was $375.
I'm currently looking for long lens alternative to the Sigma (actually, I ordered an "ugly" 300mm f4 for the heck of it.) I use the Pentax unless I really need the extra length. I often say "eh..." when viewing my Sigma images (at the long focal lengths), but rarely if ever with the Pentax.
I did an informal test of the Pentax vs Sigma at 100mm and 200mm (I could not set the FL exactly however, but close enough). I give the Pentax the slightly better grade in both cases. Pentax on left, Sigma on right.
I did not use a tripod but probably should have to eliminate that variable, However, I shot a couple with the Pentax and 6 or so with the Sigma and used the best one.
And, there may be a difference in performance stopped down a couple more stops.
Hope it helps.
100mm:
http://i133.photobucket.com/albums/q78/KylePix/Tests/PentaxVsSigma100mm.jpg
200mm:
http://i133.photobucket.com/albums/q78/KylePix/Tests/PentaxVsSigma.jpg