Lens Not Focusing

[rob14]

I have a Canon 50mm f/1.8 that seems to have lost its ability to focus.  I know this is a "cheap" lens but it has not suffered any falls or damage.  There is nothing rattling around inside.  I am using it on a 6D.  The lens constantly is rotating trying to focus but never actually does. 

Any ideas what could be wrong?  Anything I can try to remedy the issue?

Thanks!

[bseitz234]

Is it not locking focus, or are the actual lens elements not moving?

When it tries to focus, you should be able to tell if the physical focus is at least changing. If you can hear things moving and the actual focus of the lens is not changing at all, my guess would be that somehow the motor has become disconnected from the focus group, and you'll have to send it back to Canon.

If it's trying to focus, and just not confirming or locking focus, I'd be curious what you're shooting. Can you add more light, or focus on something higher-contrast? What focusing mode on the camera are you using? Is there another camera you can borrow from someone to test it? If you throw on a speedlite, does the AF assist beam help at all?

Just my initial thoughts on how to better diagnose the matter...

[J.R.]

Are you able to focus manually?

[AudioGlenn]

how close are you to the subject you're trying to focus on?

[rpt]

All three responses are gems. You need to check your lens behaviour with respect to each of these responses.

[jimjamesjimmy]

is the lens cap off?

[OKO-SAN]

1) Confirmation tone focus in manual or auto mode. When a signal is try to open the aperture and maximum use sunlight outdoors or infrared light external flash. 2) Clean the contact lens with the body, flip through the manual-auto switch on the lens a few times, rotate the dial aperture in manual mode a few times, may have dust on any contacts. 3) Turn off the camera, remove the battery, hold the body without the adapter, and then insert the battery, turn the camera (reboot). 4) Try a different lens.(Google english)

[rpt]

is the lens cap off?

LOL! Really! The poor guy is having a bad day. Don't pick on him.

Good one though. Made me laugh.

[rpt]

1) Confirmation tone focus in manual or auto mode. When a signal is try to open the aperture and maximum use sunlight outdoors or infrared light external flash. 2) Clean the contact lens with the body, flip through the manual-auto switch on the lens a few times, rotate the dial aperture in manual mode a few times, may have dust on any contacts. 3) Turn off the camera, remove the battery, hold the body without the adapter, and then insert the battery, turn the camera (reboot). 4) Try a different lens.(Google english)

OKO-SAN has a point. If it is electrical contact related...

Would like to know how it gets resolved. And then there always is Canon service centers...

[smithy]

It's an interesting problem.  I'd recommend simply sending it to Canon for repair.

During a location shoot about a week and a half ago, my 50/1.8 started malfunctioning... again, it was a focus issue.  It was 'missing' focus on every shot.  Luckily my client (and subject) is a photography teacher and knew that gear sometimes failed.  I changed to my 24-70mm/2.8 and got the shots I needed, in perfect focus, so everything was fine in that regard.

I won't be repairing the 50mm.  I bought it during a trip to the US in 2004 (from B&H), and it has served me well.  Now, if only Sigma would release a new 50mm Art Series lens, I'd be a happy chappy.

[Mt Spokane Photography]

It's an interesting problem.  I'd recommend simply sending it to Canon for repair.

During a location shoot about a week and a half ago, my 50/1.8 started malfunctioning... again, it was a focus issue.  It was 'missing' focus on every shot.  Luckily my client (and subject) is a photography teacher and knew that gear sometimes failed.  I changed to my 24-70mm/2.8 and got the shots I needed, in perfect focus, so everything was fine in that regard.

I won't be repairing the 50mm.  I bought it during a trip to the US in 2004 (from B&H), and it has served me well.  Now, if only Sigma would release a new 50mm Art Series lens, I'd be a happy chappy.

I'd sell it on ebay for parts.  there are a lot of buyers willing to spend a few dollars to fix it themselves.  It is very likely that the flex print cable inside has one or more conductors failed, a new one is cheap, but paying someone to do it for you isn't.