I've been looking at adding to my lens collection and while I have a couple which are "normal" lenses with a macro capability, I was wondering whether to look at a dedicated Macro lens. I found reference to the Mitakon Zhongyi 20mm f/2 lens which offers a 4.5 times magnification, and wondered if anyone else has seen or used one.

Obviously at that level of magnification you need a tripod or focus rail, lots of light and it will give you a very shallow depth of field, but for super macro (or micro) images you almost expect that sort of thing.

Any comments?