Metabones Speed Booster stuck on BMPCC4K

Hi all,

I purchased a BMPCC4K in Feb 2019 and also purchased a Metabones Speed Booster adapter for Canon EF lenses. EF-MFT Mount T Speed Booster XL 0.64x. Now it is stuck on the camera body. It won't budge.

B & H (where I purchased both the camera and the Speed Booster) is now telling me I purchased the wrong Speed Booster. But at the time, I remember reading that the one I purchased was correct.

I've been using it for years, and I've never had a problem with it not coming off until now.

Any hints to what happened, and am I using the correct adapter for this model of BMPCC4K?
I noticed lately some smudges and dust in my video and I wanted to inspect inside and clean the sensor or take it to a repair shop for cleaning.

I've contacted Metabones as well.

On mtf mount you can rotate in the wrong direction when pushing the unlock button. Once you have done that you won’t be able to unmount in the right direction. The solution is to keep rotating in the wrong direction (clockwise) a full 360 degrees turn. Once you’ve done that everything works again as expected.

Maybe something like that happened without noticing?

Thank you. I got it off. Turns out it was a user error! I don't take it off of my camera body, so I was pushing the wrong "release" button! I feel pretty dumb. I was also doing this in my dark editing bay, so I didn't actually see the lens release button. Then I brought it into some light and voila, the magic button appeared and it came off easy.

Great hint. Had no idea you could do that.

Great hint. Had no idea you could do that.

I bet you’re not using nikon glass on your mtf camera with a speedbooster. “A donkey never hit the same stone…” It happened to me too many times and everytime it’s an scary experience, just for sounds it produces.
I want to take the nikon glass of the speedbooster and instead push the unlock button of the mtf mount. Even when I realize I pushed the wrong unlock button, I somehow already turned the booster the tiniest bit in the wrong direction. No way to get around it after that (that I know of).

My BMMCC the lens release button now stays jammed and won't press down to allow me to release the Metabones x58 speedbooster. Is there a safe way without causing damage?
It was a tight fit when I put the Metabones onto the body.

I’m not sure, but it almost sounds like it may not have been seated correctly. Do you recall hearing a click from the mFT mount when you mounted the SpeedBooster?

Send a note to Metabones to see what they recommend, but I’d also try gently turning the SpeedBooster in both directions while pressing the button to see if that affects the release button.