[LRflex] Re: Summicron lens on FourThirds (Revisited)
- From: William Abbott <wbabbott3@xxxxxxxxxxx>
- To: leicareflex@xxxxxxxxxxxxx
- Date: Thu, 20 Mar 2008 09:55:44 -0700
David,
Don't grind off the lens lip, grind off the chip!
Using a second, sacrificial adapter and chip, or chance your bought-
and-paid-for one, grind it away to increase its inner diameter until
it no longer works. Back off .25 mm or so and grind another.
You could have your dentist x-ray the chip to see where the leads go
from the pads. That may give you a non-destructive idea of how far the
chip could be shaved off. My guess is that all the pad area is not
really required, i.e., smaller pads will work, but I may be wrong. The
"wires" from the pads to where ever they go may be the big problem, or
maybe not.
Got a Dremel tool handy?
Best of luck,
Bill
On Mar 20, 2008, at 9:27 AM, David Young wrote:
now (on list or private mail) what lenses you have that have this
"lip" or "ridge" sticking out the back.
Some days ago, I posted the following:
For those who are interested in this sort of arcane stuff...
A photo, showing the problem of the "lip" on a old style 50mm
Summicron hitting the FC chip on the Leica-R to 4/3rds adapter, can
be seen at:
http://www3.telus.net/~telyt/lip.htm
This "lip" is, I am sure, on the lens so that when the lens is put
down, rear element down, the element will not contact the surface,
thus preventing scratches. On a Leica, or even on a Canon, this lip
does not get in the way. But, with the Focus confirmation adapters
for the 4/3rds cameras, when the lens barrel is moved towards the
film plane, the "lip" hits the FC chip. :-(
Finally, I got a chance to measure the adapter... (finally found my
metric rule... and some time!)
The inside "throat" of the Leica R to Four Thirds adapter is 42.5mm.
However, the Focus confirmation chip sticks into this gap a full 6mm,
so any lens with a lip equal or larger to 42.5-12mm = 30.5mm in
diameter, will be unable top focus to infinity, due to the "lip" or
"guard" hitting the FC chip.
It seems there are only two solutions for such lenses. Either (a)
grind the lip off - or at least that part of it which interferes with
the chip, or (b) purchase an adapter without the focus confirmation
chip.
To more clearly explain this, I have added a diagram at the bottom of
http://www3.telus.net/~telyt/lip.htm
If anyone here has a better idea, I'm open to all of 'em!
Cheers!
---
David Young,
Logan Lake, CANADA
Limited Edition Prints at: www.furnfeather.net
Personal Web-site at: www.main.furnfeather.net
Stock Photography at: http://tinyurl.com/2amll4
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