Making Schneider-Kreuznach LS lenses for Phase One 645DF

Although this was uploaded a month ago I've only just come across it, and it's interesting not only for some behind the scenes look at the Schneider factory but also for a rather clear explanation of why chromatic aberration is not visible in film and yet is a problem for digital cameras. The result is that lens makers are having to work to much tighter tolerances when designing new lenses, and is equally applicable to Nikon and Canon DSLRs as it is MF.