I recently acquired a used 355mm f/9 Repro-Claron from Schneider-Kreuznach in a Compur 2. According to Schneiders serial no. list, it was made in the 1964-1965 time frame. As a process lens with 4 lenses in 4 groups it is similar in construction to Apo-Artars or - Ronars. Both lens and shutter are in very good condition and do not look like its an aftermarket adaptation of a process camera lens. When I tried it out, I noticed that the ground glass image wide open was fuzzier than I would have expected from this type of lens and that the lens showed _significant_ focus shift, about 1.5mm going from f/9 to f/22. Some test shots showed the same effect. The lens is reasonably sharp when focused and used at f/22, although not as good as a newer 240mm Apo-Ronar and 300mm Apo-Germinar I compared it to. Interestingly, the focus shift required a reduction of the distance lens-film when stopping down, which would suggest that the spherical aberration is _over_corrected for the marginal rays. Since dialyte type lenses like this are not really known for being prone to focus shift (and my 240mm and 300mm don't show it at all), my question: Has anybody else used this lens, or other Repro-Clarons (_not_ a G-Claron, which is a plasmat-type lens), like the 210, 305, or 420mm Repro-Claron? Experiences? Is this the way they are, or did I just get a flawed one?