Re: [Leica] Lens wt vs finish->Now question about titanium

[Rick Floyd <rick_floyd@hotmail.com>]

Mark Walberg wrote:
> 
> So,then, the titanium ones are titanium over brass?  Why do they have to
> make them titanium over brass instead of straight titanium.  It doesn't
> really matter to me because I will very probably never own a titanium
> barreled lens.  I am just curious about this.  Is it because titanium is
> hard to machine?  I see plenty of people (with surplus cash) riding
> bicycles with all sorts of machined titanium parts on them.  If bicycle
> makers can machine titanium, I suppose Leica could, too.
> So, why titanium over brass instead of straight titanium?  Or maybe just
> some parts are titanium, the rest brass.  If so, which parts are titanium?
> And, how do they get the titanium onto the brass?  Is it plated somehow?
> How thick is the plating?  Has anyone ever worn through the titanium to the
> brass?

Mark:

The titanium finish is exactly that.  A finish applied to a normal brass
lens.  A titanium lens barrel is certainly "feasible".  However, "affordable"
may be the problem.  In fact, a titanium lens barrel would greatly reduce the
weight of the lens.  The titanium finish is usually applied via a vapor
deposition.  I'm not sure if this is how Leica applies the finish or not. 
Since titanium is extremely durable, I doubt that it would wear through the 10
to 100 micrometer (typical) thickness.

Rick