View Full Version : Stitching error ...
11-04-2009, 11:20 PM
I've been getting the same errors on nearly every pano I shoot and I simply cannot figure it out.
Basically, using a D300 with Nikon 10.5, Nodal Ninja 5L. I'm shooting 7 around and 1 up.
Everything seems to go fine but the final product always has very small stitching errors with the zenith.
If I stitch without the zenith all is good. When I add the zenith I get errors near the top.
Any ideas? I'm not sure if it's a setup error, a control point error or a work flow error.
Here are a couple of samples:
Any help would be appreciated.
11-05-2009, 12:01 AM
Try shooting 6 around with the camera/lens tilted DOWN 10 degrees. Then take 1 x zenith.
What software are you using to stitch?
11-05-2009, 02:53 AM
in special situation you see this problem with the zenith. I suppose in this case it looks like a problem with the controlpoints. With 6 shots around you will have an overlap of 32%. Sometimes, to get some more information for the software, it helps to take 2 shots with 60¬? up (pitch) with 180¬? turn around.
You find these things when there is not too much structure in the overlap, white walls, straight lines, ceilings with same patterns.
We have to know what software you are using and when you like to send the photos and the project file i can try to figure the problem out for you.
As mentioned in the other replies, a single Zenith shot does not provide sufficient overlap for the other images taken horizontally when using the Nikon 10.5mm lens.
It can work if there is a lot of detail in the overlaps, but in my view not worth the risk.
I use 8 images at 45¬? intervals with the camera pointed downwards by 10¬? (-10¬?) then 4 images at 90¬? intervals with the camera tilted up at 50¬? (+50¬?) and no additional Zenith shot and PTGui always has no problem (so far!).
As Andrew says, you could get away with 6 images at 60¬? intervals, but 8 works for me.
The secret is to get enough overlap, but not too much as this means getting overlaps with other images. I tend to aim for 50%, which is probably due to my photogrammetric background.
You may like to look at my web site where I have published the results of some of my experiments.
11-05-2009, 05:07 AM
I used the D300 with 10.5 for awhile and the best work flow for me was the standard 6 around one up one down.
Double check all settings are the same when shooting the sequence (shutter, aperture, WB, ISO, focus). Also make sure image preview auto rotation is off in camera menu.
Next to make sure you have the correct settings - 56mm lower rail and 86mm upper rail.
11-05-2009, 11:29 AM
I like this forum....
in advance, i don't have an 10.5 mm lens. But my experience with this sort of sites is the same.
First point!: use the right rail settings. Second Point: follow the rules of Bill to set up the camera.
Third Point: as a nikonian, you can use ViewNX to change the orientation Portrait/Horizontal before you add your photo to the stitching program. First stitch everything without zenith and nadir, then add your nadir and zenith photo one by one. Only add one photo a time. Stitch, and work away your problems.
But, walking in the desert with your photos for the software, the stitching cannot find a cross junction to stitch in the right way. Walking along a line in the dark...hard to find a good controlpoint to stitch.
I agree with Hugh, sometimes more overlap will help you to have a nice pano. The site: better take some more time to take more shots than to spend lot's of hours in the stitching or to loose a situation.
So if you like to, send the photos and the project file plus the software you use and i am quite sure you will get an advice for your problem on this forum.
11-05-2009, 03:54 PM
Thank you all. I truly appreciate your help.
Here are my files from the shoot, along with the .pts file from the latest PT GUI (mac).
I think I shot two versions of the zenith but used just one. I also shot 3 bracketed files of each position.
11-05-2009, 04:05 PM
The above FTP link doesn't appear to work in a web browser but does work on my FTP app.
11-06-2009, 02:11 AM
The cause of the stitching errors seems to be the usual less-than-optimum spread of control points. You need to add some control points into the areas that are bereft of points - particularly in those where you see stitching errors. I got a good stitch using just the normally exposed images (as HDR isn't the issue here) and discarded the duplicate images in the first position, as there are 7 around not 8. The project file is at:
BTW, there are dust spots on the sensor or lens.
11-06-2009, 02:46 AM
Thank you, sir.
That does look good. Guess I'll have to manually add some control points to these.
I've been fighting this for months. Just very small errors.
With the help of Mr. Bailey, I got a good start but I have kind of stumbled to find the proper work flow. There are a lot of boxes to click and various options in PT GUI but if you don't actually understand what they are doing, it's really not "learning".
I'll pay more attention the the control points from now on and hopefully this will help me out ... I have a LOT of panos to create.
11-06-2009, 06:46 AM
David, If you have many similar panoramas shot in the same configuration, you should be making use of a template to initialize the lens and image parameters (via File->Apply template). Having evaluated a good set of lens parameters, it is pointless repeating that over and over again from scratch. You might use the project file I produced as a template, though for HDR purposes, you need to add and link the other sets of images to form the full template.
11-06-2009, 09:23 AM
In addition to John's solid advice some tips.
When the number of images and the tilt etc. for all images is the same you can even set the calibrated template as "default" in PTGui.
Often you don't need to set extra manual CP's when using a good calibrated template and all you have to do is to align (optimize) the images for the image params yaw, pitch and roll and to optimize the lens shift params d and e with the auto generated CP's.
Only when there is absolutely no play between the mount and the lens, or when you are sure that you didn't touched the lens between pano shoots, you can skip optimizing of the lens shift params but for most camera/lens combinations and in most situations it is best to include this step.
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