So here is the whole setup that I have been using.

Canon 70-200 f/2.8 (77mm filter thread)

Step down ring 77mm to 52mm (not ideal as it causes a lot of vigneting but most L series lenses are 77mm.

Reverse ring adapter 52mm male to 52mm male.

Sigma 28mm f/2.8 with manual aperture ring (52mm filter thread).

Basically every piece couples with the following in the order I listed them.

I could go about all the technical stuff but there are people that had already published this information and explained better than I could. So here are two of the links that I have checked:

Have fun.