[Leica] OT: Technical Question- Panning vs WA Lens

[rgacpa at yahoo.com (Bob Adler)]

Thanks to all who have given thought to this question. Sorry to have been 
missing from the thread; lots of other work this afternoon.

As the Esteemed Dr. Ted would say, and as Henning implies, stop talking and 
go 
shoot! ;-)

So that I will. I will go out this weekend, after I get the rail to adjust 
for 
the nodal point, and take some images panned with the 80 and with the 40. 
Then 
we'll see the differences (I will post).

Also, in answer to Herb's good question, Photoshop and other programs do 
seem to 
accommodate for the lack of perfect flatness. 

The Arcatech GP bullheads both (the "s" and non-"s") have a 25lb capacity. I 
have no hesitation using it with the Hassy.

So thanks again everyone. I'll share the results.
Best,
Bob

PS - My guess is that I'll get up there having tried to plan this whole 
weight/flexibility thing out and, after the first day of hiking with the 
Hassy, 
I'll end up taking only the Lumix with me the rest of the time. I can hear 
Tina 
chortling now...


 Bob Adler
Palo Alto, CA
http://www.rgaphoto.com




________________________________
From: Henning Wulff <henningw at archiphoto.com>
To: Leica Users Group <lug at leica-users.org>
Sent: Mon, April 18, 2011 6:17:34 PM
Subject: Re: [Leica] OT: Technical Question- Panning vs WA Lens

This topic is a lot more complex, the answers are a lot more varied and in 
the 
end, almost everything is possible.

First, you have to determine what type of 'panorama' you want.

You can produce a wide angle photo of basically three types:

Type 1: rectilinear, like a good wideangle lens produces. What your 40 
Distagon 
would produce, or an Xpan produces.

Type 2: cylindrical, like what a Cirkut camera produces or what a Noblex, 
Horizon, Widelux (manufacturer: Panon) or Roundshot produces.

Type 3: Fisheye.

Each has advantages and limitations.

Type 1 cannot have a diagonal angle of view of 180?; in fact, as a one shot 
more 
than 125? is difficult and you need lenses like the Hyergon to achieve them.

Type 2 can have any horizontal angle of view you want, including over 360? 
but 
not more than about 110 or 120 vertical.

Type 3 can show over 180? in any direction, and 360? around the 
circumference.

But:

Type 1 starts showing distorted 3-dimensional objects in the corners when 
you 
get over about 70? diagonal, and that gets quite severe when you're over 
100? 
diagonal.

Type 2 avoids the above, except for 3 dimensional objects close to the 
zenith 
and nadir when the vertical angle is over 70?, and horizontal lines off the 
center get bowed.

Type 3 has varying magnification to get it's job done, so rectilinear 
distortion 
is quite severe, and the objects at the images's edges is often too tiny to 
be 
of much use.

You can use Photoshop, or other more sophisticated stitching programs such 
as 
RealViz Stitcher to produce any of the above. You can also stitch multiple 
frames in a pattern like 3 across and 3 down to get hi-res images from 
lo-res 
cameras.

Another topic:

Using a proper pan setup becomes more important, the closer you are to the 
closest part of you scene, and finding the nodal point becomes more 
important 
when there is a large difference in close and far image points, and the 
closer 
you are to the close point.

Finding the correct nodal point is quite simple, and should not be taken 
from 
diagrams or calculations as it's easier and more accurate to do visually.

With an SLR or live view camera, it's easier still.

Set your camera up so that the lens axis is over the rotational axis of your 
pan 
head. Aim your camera at a thin stick that is about 2 feet in front of your 
camera, and that has a scene behind it. Rotate your camera so that the stick 
is 
at the left side of your field of view. Note where the stick is in relation 
to 
the background scenery. Now rotate the camera so that the stick is near the 
right edge of your field of view. If the vertical rotation axis is through 
the 
nodal point of the lens, the stick will not have shifted with respect to the 
background. If it has shifted, move the lens backward or forward over the 
rotation axis until the image does not shift with respect to the background. 
That's it. Note the numbers, or make a scratch, or whatever as that position 
for 
the lens is the correct one. Calibrate the setup for each lens you will want 
to 
use. If you insist on using a zoom lens, calibrate at each focal length you 
want 
to use, as the nodal point will shift, often drastically.


As you might guess, I'm very interested in this and have, besides my 8 
lenses 
for Leica that are 21mm and wider, the Xpan with 30mm, Horizon 202, Noblex 
150U, 
Roundshot 220/28, a lot of shift lenses and fishey lenses, Hasselblad SWC, a 
couple of CamboWide cameras and quite a number of large format lenses that 
cover 
between 100 and 125?.

In any case, Bob, you can use whatever lens you want to stitch. If you want 
a 
given angle of view, using longer lenses will mean more exposures to capture 
every part of the solid angle, will mean more chances of mistakes (like 
forgetting a certain part of the mosaic), more chance that something in the 
scene will change while you do your series and will give you a larger file 
in 
the end with more detail. For your purposes, I'd suggest you go for 3-5 shot 
panoramics if you are going to stitch them all horizontally, and go for a 
'flat' 
stitching or 'cylindrical', and go for a 2x2 or max 3x3 if you are going to 
stitch them in multiple rows and colums, and do all of this with the widest 
lens 
you are taking. And practice beforehand. :-)





At 12:55 PM -0700 4/18/11, Red735i wrote:
> The problem is that you will be pointing the lens in different direction
> with Panning.... which means that the image perspective is different for
> each frame....
> Perspective is always dependent on distance to the subject, but too, in 
> that
> definition is that the subject is always in the same relative angle to the
> camera.  When you pan, this breaks the rules...perspective changes.
> 
> Do you remember the old Circuit cameras that made images from a moving 
> lens?
> ( More modern examples are the Panon and Widelux Cameras...).....
> The particular perspective could not be copied compared to stitching....
> because at each and every image location ( think in terms of a swinging 
> lens
> that moves in precise increments) is perpendicular to the lens....  Whereas
> in WA lenses, the extreme right and left of the image is actually quite an
> angle from the optical axis of the lens....
> 
> The results are different....  ( not better, not worse, just different)....
> 
> The most interesting thing about this topic is that the swinging camera
> approach is most close to what your brain actually sees through your 
> eyes...
> you usually pan your head when you look at a scene...  rarely do you use
> peripheral vision, which is more like a WA lens .....
> 
> OTOH, 99.99999999999% of the population would never know the difference....
> and of those that do, 99.9999999% would not care.
> 
> But don't let an architect catch you......
> 
> 
> Frank Filippone
> Red735i at earthlink.net
> 
> 
> 
> 
> I am trying to understand if I can take a wide angle photo using
> panning/stitching with a normal lens that would look like it was taken with
> a WA lens. My specific question is if I can get the same coverage and
> perspective using an 80mm Hassy lens and panning/stitching 3 or 4
> overlapping shot as I could with the 40mm Hassy.
> 
> If so how would this best be accomplished? Standing back further with the 
> 80
> than with the 40 or just at the same spot with the panning. Would the
> image's perspective be the same?
> 
> 
> 
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information

-- 
      Henning J. Wulff
Wulff Photography & Design
mailto:henningw at archiphoto.com
  http://www.archiphoto.com

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