Archived posting to the Leica Users Group, 1998/04/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Dominique, Duncan, Erwin et al.: I have noted over the years a certain reluctance by Leitz to publish the MTF curves. I think that was in part related to the company's condescension to its users' intellectual ability in undestanding optics. It is only a recent development that some MTF curves have been issued, in particular in the Adobe format, on the Leica website. Due to the small size of the graphs, it is very hard to read these diagrams. However, it is apparent, for example, that in the R family the 180mm Apo-Elmarit is superior to the 50mm f1.4 Summilux. Please compare these MTF diagrams from Leica with the very clear and detailed ones available from Hasselblad and Contax RTS for their respective Zeiss manufactured and/or designed lenses. I agree with Duncan that whatever the shortcomings of the measurements are, an internally consistent set is provided to the user. It is thus clear that the superior Hasselbled lenses are the 38mm Biogon(on the SWC), 100mm f3.5 Planar, 180mm Sonnar, and 250mm Sonnar Superachromat. Note that the % distortion is also published and it is minuscule for the 38mm and 100mm lenses. Analogus conclusions can be drawn with respect to 35mm lenses for the Contax RTS. I found these MTF curves very helpful when I was deciding between buying the 60mm f3.5 or the (older) 50mm f4 for the 500CM. The 60mm won out and this choice was supported by published pictures in books and magazines. My slides confirn the excellence of the 60mm lens,Clearly, I think we can all agree that both optical bench measurements and slides or prints are necessary to assess lens quality. regards, Andrew Jordan