I like the MS Optics 50mm 1.1 Sonnetar. Now I see a write up on the MS Optics ISM 50mm 1.0 in M mount. At only 178 grams, nice for travel. With Gauss type lens it does not have the sonnar qualities of the former, but apparently also not the tricky coma adjustment ring. 16 rounded aperture blades.

I have not used a lens this fast and wonder how and when it will improve on the Sonnetar. Any thoughts?

Looks interesting, for digital or film,
https://www.japancamerahunter.com/20...f-1-0-m-mount/