Archived posting to the Leica Users Group, 1997/11/17
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]There is a mechanical/optical relationship between the accuracy of the rangefinder and the baselength in relation to the maximum aperture/. The equation will be published elsewhere, but here is the result: Focal length Max aperture Max aperture M3 M2, M4, M5, M6 21 mm 0.12 0.15 28 mm 0.21 0.26 35 mm 0.33 0.41 50 mm 0.67 0.84 75 mm 1.5 1.88 90 mm 2.17 2.71 135 mm 4.88 6.1 This equation then tells you that the 21 mm can be reliaby focused when the maximum aperture is f/0.12 (incredible!). At 50mm the Noctilux approximates the theoretical maximum values when attached to the M6. The 135mm seems to be overstretched when used at its maximun aperture of 2,8. Hope this info has some value Erwin