Archived posting to the Leica Users Group, 2002/03/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]In a message dated 3/15/02 8:38:48 PM Eastern Standard Time, oliverbryk@attbi.com writes: > Can anyone tell me the approximate production date of an Ernst Leitz Wetzlar > f=3.5cm Summaron 1:3.5, s/n 882556? Is there anything else of interest about > this lens? > Oliver Bryk 1951. If the speed isn't a problem, a very good lens optically. Dick Gilcreast had an interesting article on this very lens in the LHSA VIEWFINDER magazine, 3d quarter 2001. Dick wrote: "The wide open f/3,5 image is quite sharp and flare-free but showing some positive curvature of field....[he later point out that several later Leitz/Leica wide-angle lenses have the same positive curvature which can even be a benefit when shooting in the field].....a little known design feature also helped to reduce [corner] falloff further: the large meniscus shaped rear element had the effect of enlarging the effective size of the aperture as the light was directed progressively toward the edges of the image, further improving edge and corner illumination........The typical A-36 [f/3,5] Summaron has a flare-free performance at full aperture. It is very sharp over the central two thirds of the frame when shot wide open with the edges showing some positive field curvature.........The small aperture performance of the Summaron is especially noteworthy. Due to its relatively simple design [six elements in four groups] the lens retains a remarkable amount of sharpness even to the very small aperture of f/22. At this aperture, with the focus set at 5.5 feet, the depth of field extends from three feet to infinity at the center of the frame and quite a bit closer at the edges [because of the field curvature]." For those who do not know Dick, he is a professional photographer of standing who has also a profound technical working knowledge of optics and camera mechanics. His series on Legendary Leica Lenses in VIEWFINDER offers a fund of interesting and - to those who wish to discover for themselves the quality of older Leica optics - useful information. FWIW, I have recently acquired a couple of the 1958 35/2,8 Summarons, also very simple design, six elements in four groups, but with Leitz-invented lanthanum glass that permitted higher levels of correction of aberrations. Both Summarons will still today produce outstanding imagery if you can deal with the lack of speed. Seth LaK 9 - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html