Pentacon auto 1.8/50

3 generations Pentacon 1.8/50 image by René Maly (Image rights)

There are 3 different versions of the Pentacon 1.8/50. In the picture on the right you can see from left to right: the original rebranded Meyer Oreston, the re-designed "red mc" (multi-coated) version, and the final version with green printed scales. The redesign focused on the coating.

Optically only the first one is slighly different as it has only a single coating applied. The other two, marked Multi Coating, do have an improved coating on their glass elements.

The lens construction was of "Double-Gauss" type. scanned by Uwe Kulick  (Image rights)