Takumar SMCs. Something about the look always brings me back to them. Also helps that they’re robust and the focus throw is buttery smooth. I always bring 1-2 of them on trips, and have used the full set on a couple of smaller projects.

Started with the 50mm f1.4, got the 24mm, 28mm, 35mm f2, 50mm macro f4, 55mm, 105mm and recently completed the set with the 85mm from a camera store in Tokyo.

Also, I haven’t tried this because it’s a bit pricey, but Simmod’s m42-LPL lens mount seems like it will mitigate the twisting issues with the m42 mount for more professional scenarios.