EF 70-200mm f/2.8 L USM autofocus and distance indicator jump

[jcalloni33]

Hello, 

I’ve just recently purchased a new EF 70-200mm 2.8 L USM lens from mpb, and despite the site not mentioning any issues with the lens, upon its arrival I’ve had some major issues with its autofocus feature. 

When going to shoot, the distance indicator jumps rapidly up and down, and the focus in the viewfinder follows suit just as quickly. I’ve cleaned sensors, changed lighting and tried a different camera body all with the same end result. Is there an easy fix to this? Is the best course of action to send the lens back? Assuming the lens has a motor/sensor issue, what would the estimated cost and repair time look for something like this?

Thanks in advance.

[jcalloni33]

I have checked that, it occurs on both 3m and 1.5m. 

[deebatman316]

@jcalloni33 did you try focusing on something outside to see if works correctly after changing the switch position in both live view and VF. Make sure there's plenty of contrast on the subject you're trying to focus on. NO contrast means the camera can't focus. Or if you're within the lens' minimum focusing distance it will NEVER achieve focus.

[ebiggs1]

jcalloni33,

That's a verbose list and nothing really about what you need to do and that is return it. Anytime a used lens bought from a supposedly good retailer should be made good. Period. You shouldn't have to try and make it work or troubleshoot it.

BTW, wherever you got the advice to clean the contacts, stop using that source. Cleaning the contacts rarely to never (more never) works or helps and can cause irreparable damage if done incorrectly. Return it today.

[SignifDigits]

I have had excellent experiences with MPB though I've never had to return anything.  I agree with ebiggs1 in voting for a return unless someone here give you a magic pill solution.  And that seems unlikely so far.  I'm sorry to hear that you're having an issue.