Autofocus with Metabones, Lumix GH5S, and EF 70-200

[Sniffen22]

Hi all! I just got the canon ef 70-200 for my lumix Gh5s with a ef Metabones adapter. I don’t know if it is the lens itself but it seems to be really struggling with the autofocus. It can kind of find focus but doesn’t really track and it makes a rapid machine gun noise when I shoot video. For pictures it is quite slow and sometimes maxes out at infinity and stays there. I have heard nothing but good things about this lens so I thought it was a must have for my camera and future cameras. Should I exchange the lens and see if is faulty or should I just return it and get a lens native to my camera body?

[AtticusLake]

This looks to me like a question for Metabones, not Canon.  They are basically reverse-engineering the EF comms protocol, and it's not really possible for them to support all the lenses.  In fact they don't even claim to.

So one thing you should do is check if Metabones actually supports your lens.  You haven't said which lens you have -- there's more than one Canon EF 70-200mm.  But you could check the compatibility list on the Metabones website: https://metabones.com/products/details/MB_SPEF-m43-BT5

In general, getting a native lens for your camera (or a native camera for your lens; it could be cheaper) is going to be the safest option.  The farther you stray from this, the more risk you take.  If you mix AF lenses and cameras from different companies, you will generally be on shaky ground.

[Sniffen22]

Thank you for taking time to look at this and sharing your thoughts. I have the Canon EF 70-200 f/2.8 USM II lens and I have the Metabones speed booster XL 0.64x adapter EF-MFT mount. My prior research led me to believe that it was compatible so I that’s why I thought it could be a canon issue with the lens.

[AtticusLake]

Well it could be a bad lens, but that would certainly not be my first guess.  You have to understand that Metabones is basically trying to "hack" the EF comms protocol, and they can only do a partial job of this at best.  That's why they publish a list of compatible lenses, and the level of support for each lens -- "Accurate only on newer cameras", "Inaccurate", "Manual focus only", etc.

Oh, and it could also be the GH5.

So if I had your problem, my first recourse would be to talk to Metabones, or post on a Metabones user forum; or maybe Panasonic.  If you really suspect the lens, then your best bet is to confirm that by trying it on a Canon camera.

[kvbarkley]

You have 3 manufacturers here. I don't know that you could ever figure out who is causing what incompatibility.

[ebiggs1]

"You have 3 manufacturers here. I don't know that you could ever figure out who is causing what incompatibility."

Actually it is not a Canon fault at all. Canon makes lenses that work on Canon cameras. Period end of story. Its up to any other manufacturer to insure their gear works with the Canon lens. There is where you need to inquire.