Video with Peter Karbe on how Leica designs and builds its Leica SL lenses
Related: distortion, Leica, Leica SL lenses, optics, Peter K, quality control
This video with Peter Karbe of Leica has many interesting insights into how Leica designs and builds its Leica SL lenses. For example, substantial effort went into quality control and “desensitization” of the spacing of lens groups (starting around the 35:00 mark).
The claim is that real lenses have MTF very close to the computed-from-model MTF. But why not measure real lenses instead of making a computed MTF chart, for credibility? And why not show useful apertures instead of uninformative ones in the spec sheets.
@1:13:24 “calculated not measured… if we measure we measure the lens without the sensor… we implement distortion compensation and color distortion compensation within the system… that’s different the MTF curves we publish and what the image delivers…. we need to do some MTF charts I think”
In other words, the MTF chart as published will generally be better than a real lens, at least for the APO-Summicron-SL lenses. And it could be unreasonably better than reality when distortion correction is required (eg 28/2 APO-SL). For the Summilux-SL lenses, real results might be better in some ways than the MTF charts (at least off-axis) when correction for lateral chromatic aberration is done.
