Irix Edge Filter Adapter for 21mm with Cap

The Irix 21mm f/1.4 has no usable front thread, so this adapter gives it one. It bayonets on where the lens hood goes, which is quicker and steadier than a screw fit, and presents a 105 mm thread for standard round filters. Designed around the lens, so it does not vignette at 21mm.

A cap ships with it, flat topped and marked, so the lens can stand on its front between setups and the filter surface is covered in transit. Irix makes the UV and Protector, Circular Polariser, Light Pollution and Full ND in 105 mm to suit.