>>3589221they're pretty neat.
pic related.
fuji xt-2 with m42 pentax 85mm f1.9 + zhongi speedbooster.
I would get some nice portrait results. i ended up selling the pentax because the all metal made it pretty heavy in my bag or even when shooting regularly. still over most of the frame it was decently sharp. its ok also as you don't expect to see every pore when you crop in to 100%