Archived posting to the Leica Users Group, 2012/02/04

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Subject: [Leica] Pano stitch test: Sunset light
From: mark at (Mark Rabiner)
Date: Sat, 04 Feb 2012 13:41:41 -0500

Not to sound silly but I kept looking back and forth trying to figure out
how into the corner you were talking about. Looking for matching blades of
grass patterns. Could not find them.
because if one is talking about the very corner what difference would it
make? Even in the days when we printed full  frame black borders with an
enlarger it was hardly an issue.
I'd also like clarified one of these days this concept which comes out: "
(relatively symmetrical) ".
Can one lens really be less symmetrical than an other?
Because part of me thinks a lens is either retrofocus or its not.
Visa versa symmetrical or not.
And if there is a blurring of those two widely differing optical concepts in
one lens I'd live to have this shown and explained to me with the little cut
way chart of the lens with its optical groups showing.
I've heard this expressed countless times on the lists: "relatively
symmetrical" and as of late I've just started to think it may one of many
internet photo chat list myths.

When is a Biogon not an Biogon? Can it be ALMOST a Biogon?
Inquiring Rabs' want to  know.

Mark R.

> From: Paul Roark <roark.paul at>
> Reply-To: Leica Users Group <lug at>
> Date: Sat, 4 Feb 2012 09:04:02 -0800
> To: Leica Users Group <lug at>
> Subject: Re: [Leica] Pano stitch test: Sunset light
> Richard,
> Very nice shot.
> One reason I've been experimenting with the very wide angle lenses is
> that they allow me to keep the center of the lens at the horizon
> (really helps with stitching) but crop the final such that the horizon
> is not in the center.
>> Now I want to combine it with focus stacking and Scheimpflug is your 
>> uncle.
> This is where the parallax issue comes in and you are much better off
> with the rotation point being at the lens nodal point.  There is a
> point at which this becomes rather overwhelming, and you'll wish you'd
> carried a Canon with it's 24mm Tilt Shift (version 2 only - version 1
> was a dog).  (Personally, I leave the too-heavy cannon at home and go
> with a non-stitched, very-wide focus stack to get the near-far
> sweepers.)
> I used a Rollei SL66 for years, due in no small part to it's built-in
> tilt.  A huge disappointment with it, however, was the close corner
> performance of the 50mm Distagon.  All retrofocus optics I've used and
> tested show the same problem of sensitivity to focus.  The ZM optics
> are no exceptions.  See the comparison of the 18mm ZM Distagon
> (retrofocus) and 21mm C-Biogon (relatively symmetrical) at
> .
> This appears to be typical.  (I have never tested the Leica 18mm.)  I
> suspect that floating elements are the best and maybe only cure for
> the focus sensitivity of non-symmetrical designs.
> Paul
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> Leica Users Group.
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Replies: Reply from richard at (Richard Man) ([Leica] Pano stitch test: Sunset light)
In reply to: Message from roark.paul at (Paul Roark) ([Leica] Pano stitch test: Sunset light)