Discussion in 'Lifestyle' started by tenxia, May 8, 2008.
I shoot Nikon. Hope you Canon users can enlighten me.
"USM is "ultrasonic motor". All Canon EOS-system lenses have built-in focus motors. There is no motor in the body as is the case with Nikon, for example."
thats why nikon MF lenses work on new bodies, and why canon users had to get new lenses when they went AF.
nikon decided to keep things easier for their existing customers, canon decided to go with the better system even though it meant existing customers would have to get all new lenses.
it's also why there was a shift to canon for a lot of sports photographers, as in body AF was much slower than in lens AF.
it's because canon shooters aren't all broke because we make money with our stuff. unlike the ni*** hobbyists.
So almost all Canon EF and EF-S lenses have USM?
And what about 3rd party lenses? I noticed Tamron/Tokina/Sigma for Canon are about the same price as Nikon ones. Do they have an extra motor inside or something?
I don't believe the low end lenses have USM.
so how does it AF?
it uses a non-usm motor
USM just means its a quiet motor. the non ultrasonics are loud and annoying.
USM just means ultrasonic motor focusing. it's an internal system (meaning the length of the lens doesn't change and the end of the lens doesn't rotate) as compared to non-USM AF, which still has an internal motor, but isn't as quiet and changes the footprint of the lens, and spins your polarizer
wrong. some, if not most, USMs still change length. My 17-85 and 50 1.4 do, I know that for a fact.
my 10-22 doesn't, which i thought was one of the big "gets" of USM, but thanks for setting me straight
USM just (usually) means: quieter, faster, accurate, fulltime manual focuing
that is not true...
"L" glass is not the only ones to have it.... the 70-300 IS USM has it, and yet does not have full time manual.
USM is only the motor technology for the focusing. THAT'S IT. nothing else...
They use less energy, are quieter and faster as stated in previous posts, but are NOT exclusive to Canon and "L" glass only... other manufacturers are using the technology as well.
USM is pretty much equivalent to AF-S for nikon right?
but once again, 3rd party lenses that don't have this kind of motor built in, can AF with Canon bodies right?
okay from memory there is USM and ring USM (canon marketing is gay), being L or not has nothing to do with it (except that most should have ring USM)
no one has any comment on 3rd party lenses?
Never bought any 3rd party stuff, so I have no input here.
You're describing IF (internal focusing). Where the lens elements move inside the housing instead of the housing extending/retracting. Some 3rd party lenses do this.
My Tamaron 90mm macro has a motor. It's noisy compared to the Canon lenses.
All Canon EF and EF-S mount lenses have AF motors in the lens. Some motors are better than others.
all third party lenses for canon will have some kind of motor. nobody wants to buy a lens that doesn't af
you'd think 3rd party canons would cost more since they have that extra AF motor inside (as opposed to nikon versions).
But canons are priced the same, if not less. what gives?