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Richard, Technician
Category: Camera and Video
Satisfied Customers: 36526
Experience:  Extensive knowledge in a very wide range of subjects
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I have a Tamron 70-200mm f/2.8 lens and I am using it on my

Customer Question

Hi. I have a Tamron 70-200mm f/2.8 lens and I am using it on my Canon 5D Mark III. I have been having problems with the autofocus. When trying to focus, it just makes rapid focus-type sounds over and over, but will not focus and I can't get the picture to take by pushing the shutter button.
JA: Has your Canon done this before? And can you guesstimate how old it is?
Customer: My Canon doesn't do that with any other lens. My lens is about 1.5 years old, and my camera is about 1 year old.
JA: How long has this been going on? What troubleshooting have you tried?
Customer: This has been happening for the last couple of months. I haven't done any troubleshooting, I have just been using other lenses.
JA: Anything else you want the electronics expert to know before I connect you?
Customer: I don't think so.
Submitted: 8 months ago.
Category: Camera and Video
Expert:  Richard replied 8 months ago.

Hi there and welcome

Can you remove the battery please then hold the shutter button down for 60 seconds then release.

Wait 5 minutes, put the battery back in and try to turn it on.

Tell me please if it now focuses correctly

Thank you

Customer: replied 8 months ago.
I won't be able to try it until I get off work, but I will. I'm not sure how this will work, though. It is only on the Tamron 70-200 lens that I have the problem. I use several other lenses, and they all work fine. I will let you know.
Expert:  Richard replied 8 months ago.

I understand but we want to rule out any firmware issues with the camera that can cause this.

It interacts with different Lens in different ways.