The Lumix G90 has the same problem with the camera hanging. I used sigma 17-70 and 55-250 lenses. I noticed that the problem appeared when I attached the viltrox and the camera to the same tripod pad with two bolts. Apparently it has something to do with the total mass of electronics. After that, I stopped attaching the adapter to the pad with a bolt. The problem has disappeared for now. And if the camera freezes, then you need to disconnect viltrox and attach it back. The camera will return to working condition. I also put duct tape under the adapter so that it sits rigidly. Everything seemed to work on the last shoot.

My Panasonic GX85 started having horizontal blue lines go across the screen, then it started freezing (like it did on the GH5 you showed here) and now my Panasonic GX85 is having this happen EVEN WITHOUT THIS ADAPTER ATTACHED! I just posted a KZfaq short called "DANGER: Viltrox EF-M2ii (Canon-mount) speed booster has ruined my camera (the Panasonic GX85)" to warn other people about this. I would also like to note that I use (and highly recommend) the all-manual Nikon-mount version of the Viltrox focal reducer (the NF-M43x) but it appears the electronic version has ruined my Panasonic GX85 (it’s been glitching on the screen since using it with a Canon-mount Sigma 17-50 2.8 EX).

The same problem. Regret buying M43 with speedbooster when having only EF lenses.

I know this is 2 years old, but if you haven't figured it out yet .......... Panasonic uses Contrast-Detect AF, with 'depth from defocus' lookup tables.' The extra glass in the adapter changes what the AF system expects to see (angle of view & aperture), and it has a melt-down. These adapters work fine on Canon EF-M and Olympus EM & OM digital bodies, and they use Phase Detect AF, with no DFD tables.

Hate this issue pls inform me if you find a solution

I blame Panasonic. They create an awesome video camera but choose MFT mount. People use Canon EF lenses on it. Metabones extorts insane money for the adapter which fails several times with different EF lenses. The most sensible step for Panasonic was to release an EF adapter & a speedbooster at reasonable price. They didn't. This is why I didn't buy GH4/5/5S even though I really wanted to. With the import price of metabones I could get a 2-wheeler!

So the Metabones didn't work with the GH7, the Viltrox locks up the GH5, but do you have at least one combination that works reliably enough to put it into a production situation?

I don't know why people don't just buy sigma 16mm and 30mm on f1.4, they're done of the very best lenses for this camera. If you need longer focal get also 56mm and complete your trio in your back and you're ready to go everywhere and shoot almost anything except very far objects

4:38 It could be the speed of your SD card. Look for the ones that has a 3 on it. For the gh5.

Lens adapter is not reliable 😭 ..... May be good for urgency .

did you read the compatibility note? :)

Hi! I had the same problem on my GH5 and my solution was duck tape the electronics of the Viltrox. I dont have the option of changing the aperture and it sucks for professional work but with this I can have the GH5 working as my second camera while I film with the S5. I don't like this solution but i don't know what to do.

not every EF lens is supported....

I have a gh5 mark 2 version and a viltrox speedbooster and if i used lenses that have pins it works fine i can change the aperture and record but if i put a manual lense the Rokinon 12mm ef on it it displays focuses even peaking is working but the aperture is not displayed which makes sense becoz it is a manual lense but for some reason it is not recording if i press the record button nothing happens i can see a good image on the screen perfectly exposed and in focus but i can`t record but the moment i put a canon 50mm stm on it the fstop is displayed and i can choose my aperture and i can record fine, how do you fix this

mhh maybe the problem is with the lens , i have 2 canon lens Canon 50mm 1.4 & 200m 2.8 and i never got freeze or any error with the viltrox 🤔.

so which adapter should I buy :)

Man same thing happens to me with my GH5 and its very annoying! Updated my firmware multiple times as well, did you find a fix?

im using it on my gh5... mount canon lens.. does any one have this problem where u try n take a pic or vid and the screen goes dark

damn hopefully my sigma 50 to 100mm f1.8 will work when i receive it. Would suck at a wedding shoot if it locked up.

3:05 “personally. I don’t like the Panasonic auto focus.” *has 3 Panasonic cameras. Reviewers will say anything to sound like an expert. 😂

I know this is an old review. I was looking to see if this was a good adapter and looking for negative reviews to help dissuade me from buying one. The first thing you did not tell us is what version of the firmware you used. Version 4 is the latest I have found which fixes problems with some cameras. That could be important as they might have updated it but looking at your lens. It is not even supported. You have the original 200mm 2.8 L That lens is not on the list for supported lenses. The 200 2.8 L II is supported on the list. but your old lens is not supported, in fact there are a lot of lenses that are not on the supported list of Canon lenses for the VILTROX EF-M2II. I am surprised it even worked on your ancient lens. The fact it did work on some cameras is a testament to the good design of the adapter. A lot of people don't even read the support list for adapters like this one. The sigma 18-35 1.8 for canon FF was not listed but people bought the adapter anyway and complained. Viltrox updated the firmware to work with this lens (though I doubt they would have updated it for an lens as old as yours). So I am going to give it a try and see if it works for the lenses I have that are on the supported list. I ordered mine today.