The Pentax 50mm f1.4 is good glass.
It has a genuinely beautiful quality wide open. Sharp on the focus point (hair in front of the eyes), but dreamy all around.
If I punch up the contrast it responds, but I really like the retro-soft-smooth contrast. Stopped down it hardens up nicely.
Something special.
With more contrast.
This acts as a 100mm on M43, but when my L mount adapter comes, I expect this, the Minolta 45, possibly the Helios 58mm, the TTArtisan 35 f1.4 (as an APS-C 50mm) and the Lumix 50mm to offer a range of tools, most being twin focal lengths on full frame or APS-C (S35). The adapted lenses can also be used as 2x crops in M43 format.