Blurry Speed Booster on zoom

I posted about this a few months back, but thought it best to start a new thread instead of resurrecting a dead one.

I'll try to summarize things to avoid being long winded:
-I have a BMPCC 4k with a Metabones T Speed Booster Ultra 0.71x so I can use my EF lenses.
-When I use a zoom lens the image won't hold a focus
-Gets worse the more the iris is opened
-My main zoom lens is a Canon EF 24-105mm f/4L IS II USM, but it effects all my zoom lenses
-The same lenses work fine on other cameras
-I returned the speed booster and was sent a new one
-Had the same problems
-There's an article on Metabones' website on how to adjust a speed booster's focal point
-It's outdated and doesn't work for this speed booster (I'm not certain it would help either.)
-I also have an old BMPCC (not the 4k) and a Metabones Speed Booster that's specifically for it
-This Speed Booster can go on the new BMPCC 4K, but it causes vignetting
-The focus issue isn't a problem when this Speed Booster is on the BMPCC 4K
-The new Speed Booster causes the same issues on the old BMPCC
-Metabones' costumer service has been non existent

I've created a video showing the new Speed Booster (the Ultra .71x) and the old one on both Pocket Cameras. I shot in 4K on the new camera and put it on a 1080 timeline to highlight the blur a bit more. The old pocket camera doesn't shoot in 4K so I doubled it's size in the editor, thus it might be a bit blurry or pixelated because of it. Also the old pocket camera was a bit harder to hit a focus with, because it's small screen (I didn't have a monitor with me.)
https://drive.google.com/file/d/1COyQeP4JSrn3zLQRvAZwspmRiQfJJMhn/view?usp=sharing

Has anyone else had similar issues or have any suggestions?

Are your zoom lenses actually parfocal? My guess is no.

The lens is not parfocal, but hasn't ever given such a huge discrepancy on any other camera (or even this camera while using the other Speed Booster.) I could try a simple EF to MFT adapter, but I feel like using the old Speed Booster and having non-blurry results seemed like a pretty good indicator that it's the new Speed Booster.

Test it with a prime lens. Does it reach infinity when it should. Make sure there is no overshoot either. If it's off, it will be off with the zoomlens as well. In that case adjust the lensgroup of the speedbooster till the prime behaves as expected. My guess is that that will improve the behavior of the zoom as well.

Thanks for the suggestion. I just tested with a Rokinon prime lens, and it is indeed way off. It keeps trying to focus well past infinity. I just happen to have finally got a reply from Metabones, and they sent me an updated diagram on how to adjust this speedbooster. I'm going to take a crack at it and see what happens.

Thanks for the suggestion. I just tested with a Rokinon prime lens, and it is indeed way off. It keeps trying to focus well past infinity. I just happen to have finally got a reply from Metabones, and they sent me an updated diagram on how to adjust this speedbooster. I'm going to take a crack at it and see what happens.

Would you mind posting the diagram here? Because I am interested in it for my Speedbooster, too.

I've included the image below, but I was unsuccessful in getting the lens to move. I've also included a video in case anyone has any suggestions or pointers on what I'm doing wrong.

Image: https://drive.google.com/file/d/12XUPK9 ... sp=sharing

Video: https://drive.google.com/file/d/1Uv2InL ... sp=sharing

I don't have that speedbooster but checked some other clips on the net and it looks like you unscrewed the correct screw (the longer one). I have the 0.58 and 0.64 and when I unscrew those, the lens block already has some play, so I'm surpriced to see yours is stuck. You might want to losen the screw of your old booster to get a feel of how easy the lens block rotates. Maybe try something like dishwashing gloves on the new booster to get better grip ...but without forcing it too much. If that doesn't work I'm out of ideas, sorry.

Thanks for the encouragement, I was wondering if I was doing something totally wrong. I wonder if Robert Niessner tries it if he'll have the same result. I'm cautious to do anything to my old speedbooster, because it works great and I really don't want to mess it up. I should wear some dishwasher gloves anyway so I'm not getting smudges on everything. Sent the video to Metabones a few days ago, but haven't heard back.

I was able to perform this task on the original BMPCC Metabones Speedbooster. So I know that it is doable.
If you loosen the screws that hold the mount to the adapter, would that lessen the squeeze factor on the lens piece and thereby lessen the friction?

I would suggest that you put a mark on the two separate pieces so that you have a point of reference of where the lens was before you started moving it.

FYI after completing the adjustment my Sigma 18-35 lens became parfocal. It was like doing a back focus.

Went back in, loosened every screw, every bolt, took the one screw I was supposed to loosen totally out, put on latex gloves, and really put my back into it. Nothing. I've checked the whole thing over for secret screws, fiddled with the little knobs and dials just incase they had some unknown relation to the lens. I can't figure it out. Maybe the whole thing has to be taken apart, but I'm afraid I might end up doing more harm than good. It's driving me up the walls.

Noticed the same. Lenses that uses to behave parfocal or closely enough on the GH5 are a complete mess when it comes to zooming on the Pocket 4K. I don't know what's going on either.

It may be the reason Metabones will release new Speedboosters soon.

Sorry to hear that, but I'm also glad I'm not alone. Are you also using the Ultra .71x?

Sorry to hear that, but I'm also glad I'm not alone. Are you also using the Ultra .71x?

The 0.64 Metabones and Aputure 0.75 Lens Regain.

On the .64 have you tried readjusting the optics? There should be a tiny flathead screw somewhere on the side that if loosened will allow you to turn the Speedbooster's lens. I tried on mine, but the thing is stuck solid. Adjusting this correctly (it might take some trial and error) might fix your problem, or at least make it less noticeable.

Did you ever fix this? I have the same problem and I've adjusted the back focus to the point where it fixes the overshoot but then can't focus closely. Also have the zoom focus problem.