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 -~----------~----~----~----~------~----~------~--~---
