Hi Bill, thanks for sharing the detailed information about your workflow.
to my understanding, the issues at Zenith and Nadir are shooting issues, not stitching issues. The upcoming new Layout with XYZ parameters may be of help for you with off-center nadir shots. To ease manual placement of the nadir / zenith you can numerically transform the panorama (pitch -90 or + 90), make the placement, and then numerically transform in the opposite direction (pitch +90 or -90). What might also be helpful for you is a zoom in the panorama viewer. You can simulate it currently by shrinking the FOV after pitching the panorama and before dragging the nadir or zenith shot (which with the fast preview is really smooth). Once everything is in position, you can revert to your overall FOV. But I'm still skeptical about the benefit of manually placing the shots. Other than that I don't see how the software could help you to a better / easier / comfortabler stitch. Where are can I see your wilderness panos? Yuv awbrody wrote: > Hi Yuval, > > I take my panoramas in wilderness environments, often in the mountains > where the weather and the light is dynamic. Often the position is > somewhat precarious such as on a glacier near a crevasse. In general I > like to photograph with the camera at my eye level so the final > panorama is my view immersed in the scene. The camera setting is f/13 > - f/16 for depth of field at 35mm so I need to take 12 shots for each > row. In practice this takes a few minutes per row since I often need > to use manual focus and take more than one shot to accommodate near > and far imagery. I use a Sony DSC-R1 on manual setting. The final > panorama is 24,000 pixels wide. > > It is hard to get good control points for the nadir for a number of > reasons. I sometimes shoot the nadir handheld, in which case the > images are often motion blurred and of course the camera position is > not exactly that of all the other images. I even made a surpension > system for my tripod head, to cantilever my camera and hold it > pointing down. I move the tripod and then approximate the camera > position. The height is close to the original. Even using the > suspension system I find it hard to get good control points unless I > artificially introduce recognizable objects into the scene because > the nadir is often filled with a lot of fine detail like blades of > grass or a field of like-sized pebbles. > > As for the zenith, the difficulty lies in that either there are > interesting clouds which means that there is also generally wind and > hence rapid changes in the clouds with corresponding issues in > alignment or the sky is clear and taking a series of featureless blue > gradients seems a waste of time. In that case a multipoint gradient > generator, say a gradient generated between the midpoints of the upper > part of the top row toward a darker blue might be a useful tool. > Photoshop's gradient tool just does not do the job well. Shake has a 4 > point gradient that is better, but still inadequate. A better > generator would have a series of perimeter colors plus a central color > > > On Oct 23, 3:45 am, Yuval Levy <[email protected]> wrote: >> Hi Bill, >> >> awbrody wrote: >>> Re: > Editing the zenith or nadir of a panosphere is a nightmare; >>> Both zenith and nadir are problematic to align properly. >> I was writing of editing, as in masking, paiting, etc. In my use I don't >> see any difference in aligning images at Zenith/Nadir or elsewhere on >> the screen. Can you elaborate why those images do not align for you? >> >>> It's not all >>> that hard to get the zenith within hugin by manually placing zenith >>> shots without control points. The nadir, however, is especially >>> difficult not only to align, but also to photograph since the tripod >>> and head are in the way. >> Why do you need to place the Zenith manually? Yes, the tripod is in the >> way of photographing the Nadir, but there are ways around this such as >> removing the tripod and shooting hand held (and soon, using XYZ >> correction). From a stitching workflow perspective (as opposed to a >> shooting workflow perspective) Nadir and Zenith are exactly the same >> thing. It is one of the unsolved problem of stitching the sphere, to >> determine computationally what is up and what is down. This is why >> sometimes panoramas stitch upside down. >> >> Yuv > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "hugin and other free panoramic software" group. A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hugin-ptx -~----------~----~----~----~------~----~------~--~---
