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90D manual focus (1 Viewer)


Active member
Hello , This may seem a silly question but does the canon 90D have some sort of function where it can put manual focus to sleep. I have 2 canon EF/STM lens and 2 EF/USM lens. and the same thing is happening with all 4 lens.

I manually focus on the subject i am going to take a photo of and then i take the photo.
When i turn the focus ring again to do something else it does not re-focus.

I found that if i half press the shutter button the focus ring will work as it should.

I have timed how long it takes for the the focus rings on my lens to stop working.

If i focus on something and count to 10 then turn the focus ring it does not alter the focus.

As i say it does this on all 4 of my lens.

from Mr Keith Norton


Well-known member

I do not have the 90d, but I did not think it did anything different with manual focus than other cameras, such as the 7d2. Are all those lenses "instant manual focus override", like the 400/5.6 or 100-400mk2 or do they require intervention like the 70-300 IS II?

From my small experience with Canon (and it's the same with Nikon) only some lenses have manual focus override. Other lenses require that you put the lens in MF mode. I believe even for the instant-manual-override lenses like the 100-400 IS II, you need to acquire AF before you can override the focus. I think this exactly corresponds to your experience -- when you turn to something else that is out of focus, you cannot MF the lens until you 1/2 press the shutter release.

Is the 90d behaving differently than another Canon body you have?

I'm not really much of a canon shooter, but thought I'd at least give some feedback to your question with the best of my understanding on the subject.



Active member
Thanks for your reply , since posting here I have seen others post the same question on other forums , apparently what I described with regards to half shutter press , this is supposed to happen.

I "borrowed" this from somewhere else it more or less says same as you have said.
At least I know their is nothing wrong with my equipment.

‎12-14-2016 07:36 AM
The lens is probably just fine. Do you have "STM" version of the lens? If so, be aware that it has an electronic focusing system. This means that the focus ring is not mechanically connected to the focusing elements.

The lens needs power in order to focus. If you half depress the shutter, which wakes up the viewfinder display, then you should be able to adjust focus for several seconds.

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