shadowfox
Darkroom printing lives
Would someone be kind enough to tell me if mine is a zinc or brass top?
Not that I care that much, just curious.
Not that I care that much, just curious.

When I was shooting an M4P regularly I found it liberating. No meter- so what! I found that a hand held meter was fine. A quick check of the ambient lighting was all that was needed in most situations. Open up one stop when moving into shadow and close down one stop when the sun came out from behind clouds. The natural flexibility of color film took care of the rest. Great photographers like HCB who were doing it constantly got to the point where they could pick the correct exposure without needing any kind of meter. To tell the truth the M4P did have some deficiencies. Many, including me found that the flash sync ports would fall to pieces after a few years as they were poorly engineered. This always bothered me as a Leica should not have cheap plastic parts that break - but the M4P did!
Just a guess.. cost.
I think the brass plates were stamped and the zinc are cast. Tom A. would know for sure.
If the brass plates were machined then cost is an even bigger factor.
What sort of coatings/paint do the brass/recessed window M4P's have? Mine is well used (cough, slightly beat up!) and the black goes to silver and then the brass is barely visible underneath.
So, I'm pretty sure my M4-P has a brass top, but it's "brassing" is silver:
Leica M4-P With 50mm f2 Jupiter-8 Lens, April, 2010 by Maggie Osterberg, on Flickr
Why is that?
They were chrome (I think) plated under the black. I don't know if that was for wear resistance, or compatibility with the black anodizing.
The black chrome is called Eloxal and is a Leica product. On a brass top plate there is a "strike" of nickel on the brass and this is there to make the black chrome adhere to it. The same process is used on the zinc plate - with additional copper applied. You can strip the black chrome off a brass top - but it can give problems if you want to do it on a zinc plate. The nickel has to be stripped using a special acid and that can "etch" the zinc badly.
As for the difference in the viewfinders of the M4P and the M6 - the size was slightly reduced to allow for the diodes and also for the chrome "backing strip". I have never had a problem with the sizes - and rangefinder cameras are not designed for perfect framing anyway. Coverage depends on the distance you focus on and, when in doubt, give a bit more and crop!
Would someone be kind enough to tell me if mine is a zinc or brass top?
Not that I care that much, just curious.
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