Irix Cine Lens Cap

Irix Cine lenses all share a 95 mm front, which is convenient until a case full of identical caps has to be matched back to the right lens. These are marked on the top face with the focal length they belong to, so the cap that comes off the 30mm goes back on the 30mm.

The top is flat, which lets a lens stand upright on its cap between setups and keeps a case packing squarely. There are two depths: the 11mm T4.3 has a protruding front element and takes the deeper cap, every other focal length takes the standard one. The fit is push-on and tight enough to stay put in transit.