[Brightcolours]

A little concern about the 43mm filter size; which is hte same as the 35f2. Otherwise positive mtf.

My Canon EF-M 22mm f3 has a 43mm filter thread too. I bought a Marumi 43mm circular-pl filter for it which is not in any way thin or low profile, and it introduces no vignetting at all. 

Only odd thing about this filter I bought is the aluminium finish (not black). Luckily that has not caused me issues (yet) (not shhoting into the sun with a pol. filter).

 



Looking at the small front element in relation to the filter size, and the relatively moderate AOV for 23mm on APS-C, I am confident the filter size is fine for this lens.