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Xem thêm: Công Nghệ Nano Là Gì ? Ứng Dụng Của Công Nghệ Nano Trong Đời Sống

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Reviews by Klaus Schroiff, published December 2008Special thanks lớn Rainer Temme for providing this lens!IntroductionThe Canon EF-S 10-22milimet f/3.5-4.5 USM is Canon"s ultra-wide angle zoom lens solution for their lineup of APS-C DSLRs. Its zoom range is equivalent lớn about ~16-35mmon full frame cameras. The EF-S naming refers lớn Short-back focus kiến thiết which is only compatible khổng lồ APS-C EOS SLRs starting with the EOS 300D (Digital Rebel). EF-S lenses feature a protruding rear element which requires a special mirror kiến thiết lớn avoid a collision of mirror and the rear part of the lens. The principal idea is the reduce the distance of lens lớn the sensor which can translate lớn a better lens thiết kế - on paper at least.
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One of the things you notice upon first tương tác is its (pseudo-)IF kiến thiết - the lens does NOT extover during zooming. There is a moving inner tube according lớn the zoom position (similar to full-frame Canon ultra-wide zooms) but this does not affect the physical length of the lens. It makes still sense khổng lồ add a filter to lớn shield this portion of the lens. Officially the lens is not sealed và therefore not dust-proof though - this feature is limited lớn recent L class lenses.The build unique feels a bit better compared its cousins like the EF-S 17-85milimet f/4-5.6 USM IS. The focus ring remains in line with the usual consumer-grade quality but the broad rubberized zoom ring feels pretty smooth. The plastic chất lượng is very decent (not yet L class quality though). The constant length throughout the zoom range certainly helps to keep the positive sầu impression.
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The lens has a very fast và near silent ring-type USM (ultrasonic) AF drive which provides full-time manual focusing in one-shot AF mode. The AF accuracy was spot on during the tests.
Specifications
Equiv. focal length16-35 milimet (full format equivalent)
Equiv. aperturef/5.6-f/7.2 (full format equivalent, in terms of depth-of-field)
Optical construction13 elements in 10 groups inc. 3x aspherical và 1x SUD elements
Number of aperture blades6 (rounded)
min. focus distance0.24 m (max. magnification ratio ~1:6
22mm)
Dimensions83 x 89 mm
Weight385 g
Filter size77 milimet (non-rotating)
Hoodoptional, petal-shaped, snap-on type
Other features-