I have just found out my cheap Fotga smart adapter for EF lenses on my A7s has a little circular space that almost exactly fits a 43mm filter (glass only, IE the edge and screw thread removed).
It doesn't seem to fit Canon EF-S lenses with filter glass in place (I am using a cheap IR filter) but EF lenses so far are fine.
My EF 100 f2 works with the IR filter in place even with the filter just loose but it can be held in with a little sticky tape if needed.
I can not help but think an apodization filter instead might be nice to use and would mean I can use it with a number of lenses.
The IR filter works ok with my 17 f4 L TS-E as a bonus.
Anyone know where (if?) I can buy a 43mm apodizing filter (glass only) or get one made?
