Mount: M42 Auto/Manual
Build quality: average
Filter thread: 49mm
Infrared Mark: no
Plastic makes it "cheapy" but light. Strange construction and use, ok pictures.
This rather unusual lens was bundles with a Mamiya 500TL auction I won on ebay. It was my first 35mm prime and has some unusual points. First, it uses eight aperture blades (quite much for a small 35mm), it uses "Vorwahlblende" which would be translated as "preselection aperture". The result is that you manually stop down the lens until you reach the preselected aperture (you preselect with another aperture ring). On the other hand, if you do not stop down until the stop, you have infinite (stepless) aperture control! Surely takes some time to get used to, but once you get the hang of it, it's nice. Sadly, the lens body is plastic. The 49mm filter thread sits inside a larger lens collar. No idea what this is good for, maybe some kind of lens shade?!
For some boring brick wall test images, look here.