see Pancolar 50/1.8 shots > https://pbase.com/kkawakami/cz_old_jena_mc_pancolar_50mm_f18_m42 This is the same as Pancolar 50/1.8 M42 mount, the other Prakticar 50/1.8 versions are all
Pentacon made repackaged Oreston 50/1.8 with possibly new multi-coating & cost cutting.