Nine mounts, one print plate: which caps I've actually tested

Every mount the cap generators support, on one plate: Canon EF and RF, Sony E, Nikon Z, Fujifilm X, L-Mount, Micro Four Thirds, Leica M and ARRI PL. A body cap and a rear cap for each. In the corner there's a front cap for a DZOFilm Vespid 100mm, because there was still room and I don't like wasting a plate.

Printing them is the easy part. A cap that came off the printer is not a cap that fits, and I don't want the website to pretend otherwise. So here's the list as it stands today.

Tested on real cameras and lenses

Each of these went on, turned with even resistance, clicked in and sat without play. Perfect fit, every one.

• Sony E: body cap and rear cap
• Canon EF: body cap and rear cap
• Micro Four Thirds: body cap and rear cap
• Nikon Z: body cap and rear cap
• ARRI PL: body cap and rear cap
• L-Mount: rear cap

Printed, not tested yet

• Canon RF: body cap and rear cap
• Fujifilm X: body cap and rear cap
• Leica M: body cap and rear cap
• L-Mount: body cap

Nothing is wrong with these as far as I know. I just haven't had the right bodies and lenses in my hands with the caps yet. The bayonets are measured from parts that already fit real cameras, the same way as the tested ones. That's a solid start, and it's still not a test. So the pages for these mounts say "measured", not "tested", and they'll keep saying it until someone actually clicks one in.

The front cap

Front caps are a different thing. No bayonet, the cap just slides over the front of the lens. The lens cap generator offers two fits: a smooth one, and a flex fit with little spring fins meant to soak up print variation.

I printed the smooth version for the Vespid 100, with the lens name on top. It slides on and stays on. No fins needed, at least on that lens with my printer. The flex fit with fins I haven't tested yet, so the generator page says exactly that.

The smooth blank cap is free, by the way, and so is the 5 mm test ring that comes with it. Print the ring first, check the fit, then print the cap.

Got an RF, X, M or L-Mount body?

Then you can do something I can't do right now. Print the fit test ring for your mount, put it on your camera and tell me what happened: goes in or not, turns evenly or not, clicks and sits without play or not. A "doesn't fit, here's where it binds" helps me just as much as a "perfect".

Write to me at b.see@focusrings.at. Every report that comes back is a step toward moving a mount from "measured" to "tested" on the site.

All body caps by mount · All rear caps by mount · Lens cap generator