Which one leh?
Which one leh?
Manual Focus... lol
Logging Off. "You have 2,631 messages stored, of a total 400 allowed." don't PM me.
I think only people who have used all 4 before can tell you. But from own experience USM and HSM are equally silent. Don't hear the motor at all but you will hear sometimes the elements inside moving around. hurhur
USM / HSM / SWM all are very silent unless u place yr ear against the lens . I have used all 3
USM is da best
Canon instroduce USM in which year? Many consumer EF have USM but you need to pay $$ to get it only in professonal model in other brands.
would some kind souls pls explain all 4 to us newbies ? Thanks!
USM-Ultrasonic motor by Canon
SWM-Ssilent wave motor by Nikon
HSM-Hypersonic motor by Sigma
SSM-Super Sonic motor by Minolta
The theory is that all uses ultrasonic wave to rotate and move the elements inside for the focussing system. It's really fast and silent. The specialty is that while lens is focus hunting, the focus ring does not move. Yet, while you turn the focus ring either way, you can manually control the focus.
The motors are all equally silent because there are very minimal number of gears inside. It's basically all the same thing given dfferent name. The noise from these systems come from the movement of the lens elements.
Can anyone tell me what is the difference between each system?
“How fortunate for leaders that men do not think.” - Adolf Hitler
All of them are already very quiet, the focus speed is more important if we are comparing the focusing system, why are we comparing somethng that is already very quiet that we hardly feel its present? Perfectionist??
If under any situation where you need to maintain total silence while taking photos, the flipping of the SLR mirror is 100 times more than any AF system.
There are some USM lenses that do not focus fast.... similarly for other lenses with "silent" motors from other manufactuers.
reminds me of my 20D " chic piak ! piak piak piak piak piak " too much of a attention seekerOriginally Posted by poh6702
the difference is canon developed this technology and employed it 10 years before Nikon does. So no suprise that USM is more widely used in Canon lenses as the technology became more mature and cheaper to build.Originally Posted by yanyewkay
there may be more differences in terms of perform, but this is hard to compare because the AF speed and accuracy also affected by the body
Minolta implemented SSM in year 2003
Last edited by Wai; 19th September 2005 at 06:46 PM.
I agree with S11loop about the amount of noise the mirror of the 20D creates....but to me....the sound is music to my ears....gives me the feeling that the camera is ''solid''.Originally Posted by S11loop
USM has two variants - USM ring type, USM micro type. the former is fast and quiet but expensive to make, while the latter is a tiny motor inside the lens...which is cheaper to make but focus is slower.Originally Posted by mpenza
micro usm is not really that fast.it is present on the 75-300 lenses and on the new 70-300 IS USM. Ring USM allows full-time manual focusing while micro does not. actually i have a suspicion that micro usm is actually nothing (same as original lens without usm), its noisier than the kit canon kit lens, and also makes a horrible squeaking sound...
There is one exception on the micro USM, the 50 f1.4 can do full time manual focusing. Dont know how they achieve it. Any ideas? I jus think that micro USM has a better motor than those normal motor . That is why they labelled USM?
the 85 1.2 is one such lens.
Originally Posted by mpenza