Mark Eggers said:
I would like to know the differance in the versions 3..4.. etc.
Thanks, Mark
Another alternative in your search is the Zeiss ZM 50/2 which I bought used from Kyle for a price comparable to that of a used 50/2 Summicron.
In regard to your question, the first four versions of Leica's 35/2 lens are all based on the symmerical 6-element double-gauss design although two of them have extra elements. The dates & number of elements are as follows:
1958 - 8 elements
1969 - 6 elements
1971 - 6 elements
1979 - 7 elements
In 1997, Leica abandoned the double-gauss design & introduced a 35/2 lens based on new design principles & using aspherical glass. According to Erwin Puts, the double-gauss design is limited by field curvature & oblique spherical aberration. The new design was employed to improve the lens in these areas.
Puts has tested all four of the earlier versions of the lens. Here are some of his comments:
1958 - Relatively large front & rear elements to reduce vignetting although some vignetting at f/2 & f/2.8. At full aperture overall contrast is low & coarse detail soft at the edgesalthough fine detail visible in the center but becomes blurred away from center & into the corners. Contrast improves markedly at f/2.8 although this is still a lower contrast lens. By f/5.6 fine detail is crisply defined until the corners, which stay very soft. There is a pronounced tendency to flare at wider apertures due to the presence of coma. Close-up performance is fair & requires that the lens be stopped down for good imagery at this distance. Distortion is negligible. The lens is very compact.
1969 - Very short lens - an economical version of its 8-element predecessor. At full aperture overall conrast is medium, higher than the previous version. Unlike the previous version, it never achieves crisp definition of fine detail outside the center. At close distances this lens has really high performance especially shen stopped down. Flare tendency at wide apertures.
1971 - Improvement in overall contrast from the previous version specifically in the center. However, this drops significantly in the center & is below that of the previous version. Flare is reduced & vignetting is lower. Overall the differences between this lens & the prvious version are small. The construction introduces a small air space in the rear group where the previous version was cemented. It is a few millimeters longer than the previous version.
1979 - Medium contrast & much improved quality at full aperture specifically outside the center as field curvature is corrected to a higher degree. Overall contrast is medium, higher than in the previous version, but the corners are still very soft Flare is limited to the outer zones. Fine detail at f/2 is recorded with soft edges, becoming quite fuzzy in theouter zones. At f/2.8 fine detail becomes quite crisp in a wide central area, abruptly becoming very soft in the corners. Begnning at f/4 very fine detail is visible except in the corners & becomes increasingly sharp as the lens is stopped down. some vignetting. This is the "bokeh king" (which has increased demand & buoyed the price). Compact & an excellent design compared to its predecessors.
