2006-12-11 19:59:56 · 5 answers · asked by free_tibet 2 in Consumer Electronics ➔ Cameras
Ultrasonic lenses (USM) have faster and less noisy auto focus than non-USM AF lenses.
2006-12-11 20:04:37 · answer #1 · answered by OMG, I ♥ PONIES!!1 7 · 1⤊ 0⤋
They are called USM lens for short (UltraSonic Motor). It's allow the lens to focus faster and quieter than standard lens. If you are looking for some nice Canon lens. Look for "L" lens. You will see a "L" after the min F-stop. (For example 70-200mm F/4L)
2006-12-12 04:16:37 · answer #2 · answered by Anonymous · 0⤊ 0⤋
the USM Canon Lenses = Ultrasonic motor = very fast autofocus + a quiet one.
2006-12-12 08:03:37 · answer #3 · answered by dand370 3 · 1⤊ 0⤋
Quite different as the the motor is in the lens - faster focusing.
You should check out an Image Stabilization lens also.
Those are really expensive...
2006-12-12 05:35:31 · answer #4 · answered by Jon W 5 · 0⤊ 0⤋
i don't know
i think it's cause it ca take pic from far away
2006-12-12 04:03:31 · answer #5 · answered by Hally berry 3 · 0⤊ 1⤋