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http://www.pbase.com/lightrules/uwatest
كاميار فكر كنم ميرزه 80 تومن بالاتر بدي ها
Quick comments:
*Sigma 10-20 $480, Canon 10-22 $690 [BH Pricing]. The Sigma is 70% the cost of the Canon (and includes an EX petal-type hood and EX black carry pouch).
*The Sigma renders a warmer tint (with the Canon being cooler); not a big deal, especially if shooting RAW.
*Under harsh lighting conditions (see Test3), the Canon fares better.
*The Canon tends to have slightly more "pop" out of the camera.
*Both yield solid center and edge resolution performance with the Sigma slightly better.
*The Canon has better flare-resistance characteristics.
*Distortion is present (especially at 10mm wide open) for both lenses but very acceptable being UWAs.
*CA is extremely well managed by both, with the Canon (arguably) being slightly better.
*Light fall-off is "acceptable" for both lenses at 10mm wide open; by f8 it's "negligible."
*The Sigma's AF is swift and silent (due to the HSM unit); it is also very accurate.
*The Canon's AF is "swifter" and also silent (due to its USM unit); it is also very accurate.
*The focus ring on the Canon is small, gritty, tight, and less refined than the Sigma (which is buttery smooth).
*While the Sigma is "only" 3 ounces heavier than the Canon, when each lens is "in hand" you can actually feel the difference. The Canon "feels" much lighter.
*Overall, these are 2 impressive UWA lenses with the Canon being IMO slightly better optically, though the build advantage goes to the Sigma. While I own the Sigma (and thoroughly intend to keep it), the Canon certainly impresses. FWIW, I've reviewed countless full-frame captures of each lens both on screen (and printed out some comparison 11x14's), and by and far, it's EXTREMELY HARD to see any meaningful difference, save for the difference in color tone. If you shoot in RAW, it isn't an issue at all. Both lenses will satisfy as your UWA lens in your bag. And if you don't mind starting at 12mm, the Tokie is a VERY good one too.
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