Another one of my old M42's I had lying around, this one surprised me quite a bit. I didn't expect much from it, but it is surprisingly sharp, not amazingly sharp, but surprising. Suffers terribly from vignetting though. But a decent focal length for street stuff. Some sample pics attached. Late afternoon, ISO 640, Lens was at f2.8. Post processing: VSCO Portra 160+ Alt+ and levels, sharpened for web.