Well, that sure was simple. Turns out the solution to fixing the infinity focus issue on vintage Contax-Zeiss with Metabones Speedbooster doesn’t involve using a Dremel tool. And no, you don’t have to recalibrate the lenses, either.
You just have to loosen a tiny set screw on the Metabones Speedbooster, and rotate its lens element (in my case, counter clockwise). Boom! Everything comes into focus.
Each of my vintage CY Zeiss lenses has a slightly different infinity focus point, however, so that means setting the infinity focus to the lens that is the farthest off. This means the rest of the lenses now focus beyond infinity, which isn’t really a problem. All of my modern AF Canon lenses do that by design. But it does mean the witness marks are off to varying degrees.
There’s one other issue with this fix that affects my Sony FS5: rotating out the rear element on the Speedbooster causes it to protrude further (see image below). As a result, when the Speedbooster is screwed into the FS5, it makes contact around the edges of the ND filter mechanism. That’s not ideal, but it’s a slight contact, and the ND filter functions normally. So I’m going to chase the shallow look to infinity and beyond.
I love the vintage look of these lenses so much that, before I discovered this solution, I’ve been shooting pretty much every interview I do with them. That hasn’t been an issue, because interviews never happen at infinity. But now that I have the full range of focus, I’m a heck of a lot more likely to shoot my b-roll with this glass now, too.
Want to see for yourself how amazing this vintage look is? You can rent my infinitely focusable 5-lens set of Contax-Zeiss cine-mod lenses on ShareGrid Seattle for $60/day. Set includes modified Speedbooster for use with Sony E-mount cameras.