2006-11-22 20:51:12 · 5 answers · asked by Anonymous in Consumer Electronics ➔ Cameras
These are completely different things.
DC stands for defocus control. This gives you variable bokeh - you can twist a ring to change the appearance of the out of focus areas (without altering the sharpness of the in focus area.)
USM stands for ultra-sonic motor. This is Canon's line of fast and silent focusing lenses. With Nikon it's called AF-S, with Sigma it's HSM, etc.
Regarding image stabilization, this usually gives you 2 extra stops. So you can take hand held shots with a 4x longer shutter speed than without IS. With lenses like the 70-300mm and in low light situations - situations where you'd normally need a tripod - that's a valuable bonus.
2006-11-22 22:03:19 · answer #1 · answered by OMG, I ♥ PONIES!!1 7 · 2⤊ 0⤋
USM stand for ultrasonic motor ...means a very fast lens motor to do the auto-focus. IS = image stabilization is good but will not do too much for 300 mm. That so the best is a tripod + IS.
IMHO:
IS- is good for up to 100mm (like the Canon EF 17-85 mm IS USM lens) and you keep the camera in your shaky hands ;-D
2006-11-22 23:27:25 · answer #2 · answered by dand370 3 · 1⤊ 0⤋
Usm Motor
2016-12-16 03:07:20 · answer #3 · answered by ? 4 · 0⤊ 0⤋
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2016-02-13 15:47:25 · answer #4 · answered by ? 3 · 0⤊ 0⤋
1
2017-02-10 18:10:19 · answer #5 · answered by Christian 4 · 0⤊ 0⤋