canon usm?

[CWA_JGEISINGER]

I know this will sound like a stupid question to some.

But in this lens title 85mm f/1.8 usm

what does the usm stand for?

 

[jamescell]

usm means ultra sonic motor.

 

[Urban Grimshaw]

If I remember correctly, the USM lens is quieter than the standard lens. Makes it more useful for wildlife, or simply creeping up on your sister while she's in the bath...

My memory could be failing me though, maybe someone can back me up?

 

[Jestev]

If I remember correctly, the USM lens is quieter than the standard lens. Makes it more useful for wildlife, or simply creeping up on your sister while she's in the bath...

My memory could be failing me though, maybe someone can back me up?

Yes. USM (Canon) and AF-S (Nikon) motors are quieter than usual motors and, sometimes, are more accurate and faster.

 

[jamescell]

there are two types of usm motors too. One is ring type and the other is......... I don't remember. One or both of them let you have full time manual focus. I don't remember which is better. I think all the L lens have usm motors, the 2 L lens I own have usm motors, both are almost silent and almost instant focusing.

 

[Sideburns]

I have USM on my L lens, and it's basically silent other than the fact you can hear the lens moving...
Also, it's really fast and accurate.