Ignore the camera for a moment, it's the lens you need to concentrate on here. The venerable Meyer Optik Orestor 100/2.8, made around 1970 in Gorlitz on the border with Poland, just down the road from Dresden. If you don't know the lenses, well, tough, 'cos they're quite difficult to find in M42 in good condition. The one in the pic is the first one I had, back in 2005, and which I stupidly sold. The replacement was fine for a long time though first the auto pin went, and then finally the aperture blades themselves - for quite a while I only used it wide open anyway.
But I've just found another that was going cheap (relatively) with perfect functionality but trashed coatings. Fortunately it is the same model so when It arrives I will have some satisfying fun unscrewing the lens units and transferring them, swapping them over. A ten minute job on account of the ultra logical design of Meyer's lenses.
Yes, they are better than many of the 35mm Zeiss lenses of the period. Here's an example of why I like it:
100717_acr_13 by
Sandeha Lynch, on Flickr
And another, both on Acros and a Pentax body:
100710_acr_21 by
Sandeha Lynch, on Flickr