Voigtlander Nokton 58mm f1.4. This is a very special lens.
It is MF, FF, metallic and built like a tank, petite, with an truly outstanding IQ. I presented a short, subjective comparison between the VL58mm and FA31 mm at:
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/209251-fa31...mm-f1-4-a.html.
I was suggested the VL58mm by a PF member. It was my second lens and by far my best investment. A truly outstanding lens, well worth to consider.
Personally I use the VL58mm f1.4 for both indoor and outdoor shooting. Outdoor, the lens is flawless, even in very poor lighting conditions, like fog, smoke, smogg.... However I admit that I prefer the FA77mm for portrait. (I bought my FA77mm 2nd hand from a Japan at a reasonable price.)
If you dare to be different, the Voigtlander Nokton 58mm f1.4 is for you and you will not be disappointed.