DPC Posted June 21, 2015 Share Posted June 21, 2015 I have just bought a Metabones Canon EF - MFT Speedbooster and A Tokina 11-16mm I was hoping to use it with on my GH4.The Speedbooster works fine with Canon lenses. Images are sharp and I can focus to infinity.When mounted directly on a Canon body, the Tokina works perfectly in both auto and manual focus modes. Images are sharp at infinity.Here's my problem: when I mount the Tokina lens on my GH4 via the Speedbooster, I can't focus to infinity. Worse, I can't focus further than about 4 feet (when the lens shows infinity). This makes the combination totally useless. Does anyone have an idea what might be going wrong here? I can't return either the lens or the adapter because separately they work fine. Together (which is exactly how I wanted to use them) it's a disaster. The strange thing is that I don't remember having this problem when I got two items three weeks ago. Neither has been dropped, knocked or otherwise mistreated.All help gratefully received! Quote Link to comment Share on other sites More sharing options...
levisdavis Posted June 21, 2015 Share Posted June 21, 2015 I have heard on NoFilmSchool that there is a possibility that you can adjust the back focus of the Metabones. You might want to look into finding out how that process works. Quote Link to comment Share on other sites More sharing options...
levisdavis Posted June 21, 2015 Share Posted June 21, 2015 I have a Mitakon Nikon F speed booster. I will check and see if back focus is off on that with my 11 - 16... Quote Link to comment Share on other sites More sharing options...
levisdavis Posted June 21, 2015 Share Posted June 21, 2015 Focus is spot on and appears parfocal (zoom in and focus and then zoom out and it should remain in focus) with the Mitakon. I would check on the back focus and see if an adjustment can solve that. Quote Link to comment Share on other sites More sharing options...
DPC Posted June 22, 2015 Author Share Posted June 22, 2015 In case someone else has the same problem, this is what happened: the Speedbooster was delivered with the screw that holds the rear lens element in place completely loose. At some point the element was cleaned with a cloth and moved, thus making infinity focus impossible. I have readjusted and locked the screw down and all seems to be well.I'm sure you will understand that I'm not at all happy... Xavier Plagaro Mussard 1 Quote Link to comment Share on other sites More sharing options...
richg101 Posted June 22, 2015 Share Posted June 22, 2015 be sure to only tighten the screw a tiny amount. since when tightening you'll notice the optical cell shifts to one side. this wont help since plane of focus wont be parallel with the sensor. Quote Link to comment Share on other sites More sharing options...
DriftProductions Posted October 10, 2015 Share Posted October 10, 2015 In case someone else has the same problem, this is what happened: the Speedbooster was delivered with the screw that holds the rear lens element in place completely loose. At some point the element was cleaned with a cloth and moved, thus making infinity focus impossible. I have readjusted and locked the screw down and all seems to be well.I'm sure you will understand that I'm not at all happy... Hey DPC! From what i've read extensively online, even if the screw wasn't loose many people are still having the same issue with their brandnew Metabones speedbooster coupled with a GH4 and the newer baby brother G7. I ordered the new Speedbooster XL 0.64x for Canon and i'm thinking about returning it given the issue.I don't believe cleaning and moving the element should be a fix for this issue and you may find your optics with the speedbooster are slightly out. The issue surely has to be an incompatibility with Panasonic cameras, not the lens or the speedbooster itself. Would be great to know how your getting along now and if you are still having the same problem? Have you heard any new info about this issue? CheersJoel Quote Link to comment Share on other sites More sharing options...
DPC Posted October 20, 2015 Author Share Posted October 20, 2015 Sorry, just seen this.I adjusted my Speedbooster myself initially and then sent it back to Metabones for re-calibration.I'm not sure there was much difference between my repair and the subsequent factory one.Since then I have had no problem at all and use the thing all the time. Quote Link to comment Share on other sites More sharing options...
jonpais Posted October 21, 2015 Share Posted October 21, 2015 Sorry, just seen this.I adjusted my Speedbooster myself initially and then sent it back to Metabones for re-calibration.I'm not sure there was much difference between my repair and the subsequent factory one.Since then I have had no problem at all and use the thing all the time. My Speed Booster XL was also delivered with a loose screw. Extremely disappointing for an instrument costing $750 USD. I had to take it to a local camera repair shop, it took them 1/2 an hour to set things right. It's worked fine since. Quote Link to comment Share on other sites More sharing options...
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