I want to use a speed booster and legacy lenses to fill the need for fast primes. I’ve wasted too much money on native lenses. What I’m looking for: FF like bokeh, creamy, portrait experimentation. Looking for f/1.0 (f/2.0 ff equivalent) the following resulting focal lengths (35mm equivalent, approximations): ~50mm, and ~150mm. In the future I might want ~24, and ~85. It seems like their are more m42 options floating around on eBay instead of being limited to just minolta. I have a pentax 50mm f2 laying around- can I get an k-mount to m42 adapter? Thanks!