Perplexing Panorama Photograph Problem

[KenS]

Have you tried the Photoshop's Photomerge "Reposition" (last option in the list)?  It almost always works best for my wide angle TS-E shots when I use an Induro PHQ-3 head.

Ken

[sharperstill]

I'm back.
I'm happy to report I got a good-looking-no-bumps panorama out of Hugin. See attached.
The only bad news is I'm not really sure how I did it.
My forst attempt with Hugin yielded much the same result as in the original post. I left it for while, got busy with other things and came back to it yesterday.
Starting from scratch and using only 3 images rather than 4, for roughly the same field of view, I got the result shown.
Obviously I'm still groping my way around Hugin like a sailor in a brothel but I'm pleased with the outcome.

Jon

[Bart_van_der_Wolf]

I'm back.
I'm happy to report I got a good-looking-no-bumps panorama out of Hugin. See attached.
The only bad news is I'm not really sure how I did it.

Hi Jon,

Good to know it worked out as intended.

From the looks of it, you've selected a cylindrical projection, which makes sense with such a wide field of view. That does mean that only a centrally placed horizon will be straight, and that's what you seem to have done, vertically centered on the horizon.

You can also achieve that automatically, even when your image tiles have more sky (or more land) than land (or more sky), by placing some horizontal control point pairs in each image tile, if it's easy to see that horizon like in your images. By adding those horizontal control point pairs in each individual image tile, you'll automatically force the image to a higher or lower than center image, and subsequent cropping will take care of the rest. It may cause empty areas in the outermost corners, and/or the center, so one might be required to take some additional images for those areas if the scene is predominantly sky or land.

Other projection methods offer other opportunities, but also challenges. Not all projections are available in every Pano-stitching application, some only offer a few.

Cheers,
Bart

[Petrus]

Sometimes you can get 'interesting' results!

http://www.wolfnowl.com/2010/05/panoramic-photography-and-stitching-errors/

Mike.

Similar things have happened to my panoramas when taken with extreme wide-angles. In the past there was a recommendation that the lens used for stitch panoramas should not be wider than something like 28mm for 135 size sensors. There is so much distortion in wide-angle corners that the stitching software is bound to have problems sometimes. They have been getting better in this respect, though. 17mm is wide...

[kers]

" ...I didn't think lens corrections could be applied to images from TS lenses?..."

Hai Jon, to my knowledge , the only program that can do lens corrections on TS lenses is PTlens

http://epaperpress.com/ptlens/
good luck!

Pieter Kers

[AreBee]

Petrus,

In the past there was a recommendation that the lens used for stitch panoramas should not be wider than something like 28mm for 135 size sensors. There is so much distortion in wide-angle corners that the stitching software is bound to have problems sometimes.

If control points are placed manually there is no reason to expect anything less than a perfect stitch from an ultrawide angle lens. Distortion is taken into account by stitching software for any lens - it has to in order to theoretically overlap each image exactly with its neighbour(s).

In my opinion most stitching errors derive from the user allowing the software to place control points. Wide angle lens or otherwise.

[Bart_van_der_Wolf]

Petrus,

If control points are placed manually there is no reason to expect anything less than a perfect stitch from an ultrawide angle lens. Distortion is taken into account by stitching software for any lens - it has to in order to theoretically overlap each image exactly with its neighbour(s).

Hi,

That's correct.

In my opinion most stitching errors derive from the user allowing the software to place control points. Wide angle lens or otherwise.

While true, and that's why I always double check the individual control points when there is an issue getting the stitch to work well, there are other reasons as well. The optimization process can get stuck in a mathematically optimal solution that minimizes the errors, but given the complexity of the problem there may be other optimal solutions as well, and some give better results.

It can therefore make a difference in what order the various parameters are optimized, and some programs allow to influence that. Different orders can be required for stitching rectilinear panos or spherical VR  panos, or for wider angle lenses or for normal to tele-lenses.

Cheers,
Bart

[Deardorff]

Auto pano pro does a much better job of stitching fine detail than photoshop.