Archived posting to the Leica Users Group, 2001/06/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Seth, > Phil: I think your conjecture is exactly right. Lothar Kolsch, Leica's > current chief of lens design, has clearly opted for optical design that > favors optimum performance at full aperture. Examining the photodo results a bit further shows that this is not the case. For the Leica 35/1.4 asph-M, the numbers are as follows: Weighted MTF for 35 mm: f1,4 0,54, f2 0,65, f2,8 0,75, f4 0,75, f8 0,83 Average Weighted MTF: 0,80 Grade: 3,8 Weighted MTF 10 lp/mm: 0,89 Weighted MTF 20 lp/mm: 0,75 Weighted MTF 40 lp/mm: 0,54 Compare this with the Canon EF 35/1.4L offering: Weighted MTF for 35 mm: f1,4 0,61, f4 0,82, f8 0,81 Average Weighted MTF: 0,81 Grade: 4,0 Weighted MTF 10 lp/mm: 0,89 Weighted MTF 20 lp/mm: 0,78 Weighted MTF 40 lp/mm: 0,59 If these numbers are to be believed, the 35/1.4 asph actually excels at the smaller f-stops, only bettering the Canon SLR lens at f8. At f1.4, the asph has a pretty dismal graph on the MTF chart. Cf.: http://www.photodo.com/prod/lens/detail/LeSummilux-MAsph.35_1-267.shtml and http://www.photodo.com/prod/lens/detail/CaEF35_14LUSM-83.shtml Dan