I had an Exakta RTL 1000 in the early 1970's it came with an Meyer Optik Oreston 50mm f1.8 lens. Since it was a soviet camera and the opinion of soviet cameras was not too high, I always assumed that Meyer Optik was a cheap and cheerful producer of lenses of low quality. Wrong on both counts! Before WWII, they had a good reputation and after the war ended their factory was in the Russian sector of Germany. They were taken over by the soviets. However the brand has survived and is now producing some very good lenses, probably to refined standards of their original designs that are also quite expensive.
To be honest, looking at the picture above, and many others I have taken with this lens on both digital and film cameras, I was much mistaken in my original assessment of the lens as an "also ran" It is sharp once stopped down a stop or so, has little or no chromatic aberration, little or no barrel distortion and is pretty spot on colour rendition wise close to the standard set by the CYJ Pancolar lens.
Design wise the Orestegon has the following specification:-
Focal length 29mm
7 elements in 7 groups
Aperture range f2.8 – f22 in detented half stops
Minimum focussing distance 0.25m
Aperture blades: 6
Mount: M42 and Exakta
Filter thread: 55mm
Auto Iris

When the RTL 1000 ceased it's limited production run the Orestegon was subsumed by Pentacon, who eventually marketed the lens with Pentacon branding, however, the design remained unchanged except for recalculation of the lens elements caused by a change in glass suppliers.