06-21-2020 01:26 PM
I'm noticing the auto focus on my EFS 17-55 is loud. Its different than the IS which is also noticfeable, but much less. Has anyone else had trouble with loud autofocus on this lens?
06-21-2020 02:24 PM
The EF-S 17-55mm f/2.8 IS USM should be whisper quiet for photography. It has Ultra Sonic Motors. But, if you are shooting video, then it could be an entirely different situation. However, the 17-55mm should be whisper quiet shooting stills or video.
Not all lenses that are great for photography are great for video. Many USM lenses have surprising loud apertures. You may need notice it shooting stills because the shutter will drown out the aperture stopping down, or you may shoot at or ner wide open most of the time.
But, when shooting video, there are two common ways to adjust exposure: Aperture or ND filters. On some lenses, the aperture will only seem to move in discrete steps, just like it would on a manual focus lens. I have noticed that some EF lenses behave this way, including some of them with USM.
With STM lenses, their apertures change smoothly, much like a manual focus, cinemalens with a declicked aperture ring. All of the STM standard zooms behave this way, but the STM primes do not. Camera bodies with the latest DPAF seem to know which lenses will perforrm well, and will enable Movie Servo AF. With some lenses, Movie Servo AF remains disabled.