[Leica] buy new 50mm f2.0 Summicron LTM, sell used 50mm f2.0 Summicron M?

[Hans-Peter.Lammerich@t-online.de]

Ernie,

in the first place you will loose/spend a lot of money by trading your 
used M 2/50 for a new LTM 2/50 with LTM to M adapter. Technically 
speaking the new LTM 2/50 is optically superior to any Leica or non-Leica 
LTM-lens. With the right adapter it should work on a Leica M without 
problems. 

If you want state of the art optical performance, use your “old” M 2/50 
with a Leica M. If you at times prefer the nostalgic handling of a 
screwmount Leica, use it with a lens of the same vintage (for a fraction of 
the above $$$), with some optical imperfections that will produce images 
with the corresponding nostalgic look. If you at times prefer the 
compact size of a screwmount Leica, put on a collapsible Elmar 3.5/50, but 
not a new LTM 2/50 (or new Voigtländer 1.5/50)! 

Hans-Peter