Re: [Leica] 21mm S/A metering modification (long)

[Lucien <lucien@ubi.edu>]

In November, the fearless Jeremy Kime ask somebody to modify 
his Super-Angulon 21/3,4 in the way described on the following website:

http://reality.sgi.com/jessen_esd/angulon_mod.html

> Modifying the Leica Super-Angulon f3.4 :

> TTL metering is possible.
> Not for the Faint-Hearted.

> The f3.4 Super Angulon can be made to work with the light meter on the M6 body. 
> This process involves "machining" the rear collar of the lens 
> (though it can be done with simple tools, outside of a machine shop). 

> 1.It is assumed that you are ready to dismantle and modify your lens. 
> 2.The meter will read 1/3 stop under, which is compensated for by advancing 
> the film speed dial by one notch. 
> 3.The lens should be focused to close range in order to accurately meter. 
> Close-focusing is needed to nudge the rear glass out of the way of the 
> metering eye, and can be quickly done and then un-done while shooting.
> (However, on an M6 with the spot size reduced for tighter metering pattern, 
> this close-focusing has been found to be unnecessary.) 

After modification, Jeremy Kime wrote:

> Got the lens back today, it meters.
> I think the suggestion that it would only be a 1/3 of a stop is generous, so
> far it seems to be about a stop, haven't put any film through it yet but if
> I can end up relying on it being a stop then thats a nice round number to
> deal with and still cheaper than getting that new Elmarit-M ASPH.
> I'll try and test some different apertures on the metering tomorrow.


Today I found that if you use the R-Super-Angulon 1:3,4/21 (for
Leicaflex Standard)
(same glasses as the M 3,4/21) together with the adapter 22228
(or 22228/500934) on a M6 and if you focus it on the minimum
focusing distance (0,2m instead of the 0,4m of the M 21/3,4)
you will have exactly the same result (maybe better), but without
"machining" it !
The meter will read 1/3 stop under what you will read with the M-21/2,8.
How is it possible?
Because the closest focusing distance and the fact the
top of the rear collar and of the rear glasses of the lens are already
cut 
(in order to slip under the mirror of the Leicaflex standard in the 
lock up position) give more room for the meter to read on the
white disk of the shutter curtain.

What is also nice with the R-Super-Angulon 1:3,4/21 is that you can see
the focusing scale in all the 21mm viewfinders and also the aperture
but that more easily with the metal 21mm viewfinder. 

The only drawbacks are that the rangefinder is not working with it and
the 'not-so-effective' and the big lens hood is hiding 1/4 of the image.
It served also as a retaining ring for Series VIII filters.

WARNING:
Remember that you can use the R to M adaptor 22228 or 22228/500934 
with ALMOST all Leica M cameras BUT:
Never use it with the Leica CL and send the adaptor to Leica first,
if you want to use it with the M5 (no metering possible).
With later M6s (1976 en after) the top flange of the M bayonet of the
adaptor have also to be modified (cut).

After all, it's maybe easier to buy a M-21/2,8 Asph.
;-)

Good night,

Lucien

PS- If you want to see what the R 21/3,4 + 22228 look like on a M
camera,
it's in Lager vol.2 - lenses, page 250.