[Leica] Zeiss ZM 21 & CornerFix

[mark at rabinergroup.com (Mark Rabiner)]

I'm with you on a preference of a true symmetrical design for ones best
loved wide angle lens or that's how I'd phrase it.
Other wise known as a "true" wide angle lens.
Other wise knows as a non retrofocal wide angle lens.
Which are embarrassingly just a telephoto lens... looked through the wrong
end.
And need to be five times bigger and heavier than a true symmetrical wide
which are often the size of a thimble for 35mm format.
The 38mm Biogon for the Hasselblad superwide is the first one I think of
along side of our 21 f3.4 or f4  Super Angulon. For Leica and other cameras.
And there was a 21. 3.4 SA for the R system and LTM system.
I remember Contarex has one where you locked  the mirror up and used a
viewfinder.
Center filters is what symmetric glass are said to need and there's been a
cottage industry making them for decades for all the finest lens
manufacturers making symmetrical lenses notably the German ones Rodenstock
and Schneider (JSK) for view cameras.
Though a modern retrofocal lens like the 21mm f2.8 Elmarit M ASPH is so well
corrected after years of computer design that they almost emulate a true
wide angle lens like a Biogon or SA. But I think almost not quite as far as
correction goes say for architectural use a symmetric is the lens of choice.
And its a shame the are monsters which weigh a ton comparatively.
But gee there is no fall off an the edges.
Me I'd buy a center filler which gave you fall off on the edges as I darken
the edges on every image I ever make first in the darkroom and now digital.

Sheet shooters love a Biogon or super Angulon with their amazing low profile
compactness and don't mind the amazing lack of distortion at all.
Witness the amazing history of SA use on Leica M.
There have been more than a few shooters who shoot Leica M only for that
reason. A few on the White House staff. With a nikon with a 105 on one
shoulder and a Leica M4 with a 21 3.4 SA on the other.
I've yet to score one I borrowed a modern Hassy superwide for a week and did
lots of shooting with it. Much of it on a tripod with the camera carefully
leveled. And at f11 with everything zone focused from 3 feet to infinity.
I'll love it when I can work with a true wide again. As in own one.

-- 
Mark R.
http://gallery.leica-users.org/v/lugalrabs/winterdays/


> From: Paul Roark <roark.paul at gmail.com>
> Reply-To: Leica Users Group <lug at leica-users.org>
> Date: Sun, 15 Jan 2012 08:31:07 -0800
> To: Leica Users Group <lug at leica-users.org>
> Subject: Re: [Leica] Zeiss ZM 21 & CornerFix
> 
>>> LR apparently has a built in vignetting fixer in its later versions. 
>>> ?Does
>>> LR now negate the use of Cornerfix?


It's possible that CornerFix is
>>> superior to even Leica's lens-coding
profiles.  It is custom for each lens
>>> and body.  You could even make
it custom for each aperture if you wanted.
>>> Canned profiles may be
less accurate for your particular setup.

Actually,
>>> the issue with the 21mm Biogon is that it's a symmetrical
design -- said to
>>> be terrible with the M9, with a nodal point that is
way too close to the
>>> sensor.  But symmetrical designs are, in my view,
superior in terms of
>>> sharpness and distortion to retro-focus.  The 21
Biogon is really sharp,
>>> with no distortion.   My 18mm Distagon, said
by some reviewers to be the
>>> best 18, is good, but not up to the
Biogon.  For making large prints, I was
>>> a bit disappointed in the 18,
thus the 21 Biogon experiment, which luckily
>>> worked.  But for
ColorFix, I probably would have returned the Biogon as
>>> unusable with
the
>>> M9.

Paul
www.PaulRoark.com

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