Archived posting to the Leica Users Group, 2011/04/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Bob, I have a fairly light 40mm for the blad: CFE lens I think. Is yours the 'monster' one? This 40 is smaller than my 50 f2.8 Cheers Alastair> 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 > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >