M Lens Construction

[henning]

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Usually the lenses have an outside barrel of brass, and for non-rotating lenses, which include almost all recent ones there is an interior helicoid which is aluminum and then the innermost helicoid is again brass. For non-rotating lenses two sets of interlocking helicoids are necessary at minimum, i.e., three pieces.

 

Here's the MATE, for an extreme example: https://goo.gl/yBR6FL  The yellow pieces are brass, the white (or bright. pieces aluminum.

 

Even better, here's the MATE and the Summilux 50/1.4 ASPH. Note the metal colours again. The Summilux has of course a lot more complex construction than your 35mm Summicron due to its floating elements which require further helicoids. I'm sorry, but I couldn't find a section picture of your Summicron just now. Note that the 50/1.4 has a lens mount of brass, so that it can easily be chromed and thus hardened, even though the majority of the lens is aluminum. It's a demonstration of using appropriate materials.

[Michael Geschlecht]

Hello Henning,

 

Thank you.

 

The use of dissimiler metals to reduce problems such as friction & wear was invented by clock & watch makers at the beginning of clock making.

 

These are the same clock & watch makers who later invented what became: The automobile clutch, the bicycle chain & the mechanism that powers the Leica focal plane shutter

 

Best Regards,

 

Michael