Quick tip on Manual Focus and STM Lenses

[DanSF]

I saw this video of a quick tip on STM lenses and focusing.  This issue must confuse lots of people, and even the presenter says "Review this before contacting support" so I thought I'd share here.

The author states "When manually focusing with STM lenses, an electronically powered manual focus system turns on, which may cause users to think something may be wrong with the camera when there isn't. Find out which steps you have to take before you start photographing."

http://learn.usa.canon.com/resources/videos/tutorials/quick_tips/qt_manualfocus_stm.shtml

I'm glad I saw that since I now have some STM lenses and I thought that going into MF mode & turning the focus ring is all that is necessary. Not quite true, as the camera can't be sleeping.

[zimou13]

Canon introduced STM autofocus lenses primarily to resolve an issue that their previous Ultrasonic motors could not: smooth autofocus when shooting video. In still photography, focus occurs before the image is shot, so that how the motor gets to focus is not as big a concern. But in video, focus (well specifically autofocus) occurs while video is being recorded, therefore, the relatively jerky focus from Ultrasonic motors was not preferred. There is more to it than that of course, but thats the short answer. If you are not shooting video, there is no specific reason to favor STM lenses over non-STM lenses, other than most are very new. Tutuapp 9Apps Aptoide

[RobertTheFat]

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@zimou13 wrote:

Canon introduced STM autofocus lenses primarily to resolve an issue that their previous Ultrasonic motors could not: smooth autofocus when shooting video. In still photography, focus occurs before the image is shot, so that how the motor gets to focus is not as big a concern. But in video, focus (well specifically autofocus) occurs while video is being recorded, therefore, the relatively jerky focus from Ultrasonic motors was not preferred. There is more to it than that of course, but thats the short answer. If you are not shooting video, there is no specific reason to favor STM lenses over non-STM lenses, other than most are very new.

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And a bit quieter. Sometimes that matters; sometimes it doesn't.

[Waddizzle]

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@zimou13 wrote:

Canon introduced STM autofocus lenses primarily to resolve an issue that their previous Ultrasonic motors could not: smooth autofocus when shooting video. In still photography, focus occurs before the image is shot, so that how the motor gets to focus is not as big a concern. But in video, focus (well specifically autofocus) occurs while video is being recorded, therefore, the relatively jerky focus from Ultrasonic motors was not preferred. There is more to it than that of course, but thats the short answer. If you are not shooting video, there is no specific reason to favor STM lenses over non-STM lenses, other than most are very new.

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Ditto for adjusting the aperture, which is far more noisier than focusing.  Way more.  When you use a DSLR, you do not hear the lens “stopping down” because the mirror slap drowns out the clicks.