The Autofocus Noise of Canon’s New 40mm Pancake Lens

Canon made a splash earlier this month by announcing its first EF pancake lens, the Canon 40mm f/2.8 STM. If you’re considering this lens, one thing you should know is that the autofocus noise may interfere with your videos unless you use an external mic. In his review of the lens, photographer Dan Carr writes,

Here then is probably the biggest problem with this lens. With any other Canon lens, if you think the AF motor is making too much noise you can either switch to manual focus mode to disengage the focus motors or with Canons l-series lenses and their ultrasonic motors you simply just turn the focus ring manually yourself and it doesn’t engage the noise producing AF motor. Unfortunately though, the STM motor works in a different way […] Even when you switch to manual focus mode, rotating the the focus ring engages the STM motor to move the lens elements as the whole thing is a focus by wire system. This means that there is absolutely no way for you to get a silent video. Whether you let the camera do the focusing, as with the new cameras like the 650D/T4i , or whether you do it yourself, you are going to get the background hum as demonstrated in my video

It’s an interesting quirk, since the STM technology is meant to provide smooth and quiet focus for video recording. It may be quiet (here’s a comparison with the 50mm f/1.8 II), but you can’t eliminate it completely. On the flip side, the lens is attracting rave reviews.

(via Dan Carr via Foto Actualidad)

  • TrollDaddy

    We need some filthy bootleg remixes of this now.

  • Jens Hamada

    now imagine canon would update their 20 year old EF 50mm f1.4 lens with todays technology and knowledge!!

    as good as this 40mm lens is… it is only a rather slow f2.8 lens.

    what i want/need is an updated 50mm f1.4 design (no way i spend so much money for the f1.2).

    and while your on it canon.. give us amateurs a new 400mm f5.6 with IS that does not break the bank.  :)

  • Michal Rosa

    Wow, really – it’s impossible to completely noise from a mechanical engine and it makes headlines?  Damn you Canon for not breaking the laws of physics.

  • Anon

    They could however make the mechanics oscillate a frequency above our hearing range, so it could make as much noise at it wants, and only piss off dogs.

  • Guest

    The old type lens is silent in manual mode.

  • stanimir stoyanov

    Funny, the AF noise already sounds like dubstep to me.

  • Flgraphics

    it’s a $200 lens.. what do you expect?

  • francis b

    sounds like an old school racing video game

  • dnguyen

    1.2 is gorgeous