HMC CPL clip on filter

The filter is a "Circular Polarizer" (CPL) combined with a Multi-coated UV (HMC) filter. There's a very strong built in (non-removable) clip to hold the 52mm diameter filter securely over the lenses of your smartphone camera. 52mm easily covers all the lenses on an iPhone12 mini. The clip may cover some options on the smartphone screen while using.

A CPL filter allows auto-focus to work unlike a straight line (linear) polarizer, although it had trouble refocusing in a couple of cases which was solved by removing then replacing the filter. Polarizers can act as a neutral density filter, eliminate reflections and glare, and increase saturation and contrast.

It works by placing the filter over the lens and rotating the filter until it blocks reflected light. It has the most effect when the sun is at 90° to the camera directions. The UV filter eliminates some scatter and generally increases the sharpness of photos.

This clips on fast and covers the lenses. It's just a bit larger than I'd like for carrying something for my smartphone. The case is even larger than the case for my Cokin filters I still use on my DSLR, but still fits into a daypack no problem.

I prefer a linear polarizer as I'm not too worried about auto-focus as it seems to have a larger effect, but for convenience, this works well enough.

4 stars.