18-135 USM Focus Ring Not Working

[Mike_Brooks14]

Hey guys, I've had this lens since August and it's been pretty decent. I went out to shoot the stars last night and when I got everything setup, I switched to manual focus to get the stars in focus. I began to turn the focus ring and nothing happened. I fiddled with it for about 20 minutes and had no luck. My autofocus worked fine, but manual focus would not adjust anything. I tried turning the camera off, took the lens off andreatttached, tried to manually adjusting around mode. No luck. Any ideas as to why this just quit working all the sudden?

[kvbarkley]

It is a focus by wire system, so it appears that something is broken inside.

Sometimes it seems that it takes a while to wake up the focus system, in other words, it might take a few turns to get any movement at all. Did you try that?

Are you trying when the camera is in focus/exposure mode just after you half press the shutter button?

[Mike_Brooks14]

I tried everything I could think of for about 20 minutes to no avail. I thought the STM was the only lens that required the half press, but I did try that too for good measure. I’m not sure what could’ve happened here, but it seems really strange for a lens that’s only a couple of months old. The other strange thing is that the auto focus works fine...but when I switch to manual, I can turn the focus ring but nothing happens. I tried through the viewfinder and in live view with no luck. It worked fine less than a week ago too and has been kept in a camera bag in the meantime.

[kvbarkley · Accepted solution]

If it is only a few months old, call Canon and send it back. It appears that the encoder is broken.

[Mike_Brooks14]

Good deal. Thanks.

[RobertTheFat]

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@kvbarkley wrote:

If it is only a few months old, call Canon and send it back. It appears that the encoder is broken.

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Like the OP, I thought that only STM lenses were focus-by-wire in manual mode. Is that not the case?

[Mike_Brooks14]

This is the newer nanoUSM version of their 18-135mm. Here’s a link to the exact lense. It does still use some of the STM technology.

https://shop.usa.canon.com/shop/en/catalog/ef-s-18-135mm-f-35-56-is-usm?utm_source=google&utm_medium...

[donpierson3]

I had the same problem with my 18-135 IS STM. The lens acted like it was still in AF when I switched the button from AF to M. I changed AF methods in the menu from FlexiZone to Quick Mode, and the problem went away. Oddly, when I then switched back to FlexiZone the lens continued to work in both manual and auto focus.

[Pennington]

The switch on the side of my 24-105 lens is focus/control. Manual focus does not work with either.

[ebiggs1]

This is a very old thread. You might want to start yourself a new one that addresses your concern.