Thursday, Aug 03, 2006 at 08:43
Hi Mike,
You may not realise, nor be doing any sufficiently enough detailed stitching to have seen it, but optically, it is impossible to do it with any sort of practical hand-holding.
A little exercise to demonstrate the problem.
1. Close your left eye
2. (with your right eye) line up two posts or vertical lines some distance from you (say, the door frame, and some more distant vertical line)
3. Imagine that is the image in one side of a frame that will be stitched with another (you need to remember it)
4. Close your right eye and open your left eye without moving your head.
5. Imagine this is the other image that you want to stitch.
You will see that the two vertical lines do not line up any more because you have moved a little (
well "the camera" - your eye" has moved by a few inches).
So, you have one image with two lines lined up with nothing between them, and you have another image with them separated. No amount of stitching can line them up perfectly.
The solution is to rotate around a nodal point of the lens - vertically for each column and horizontally for each row.
This is reason why your stitching (regardless of how good it is) will show discontinuous tones and lines doubled up whenever you have detail in the foreground and you are not rotating your camera perfectly.
Really too, it is important to have the camera exposure set to the same settings for each shot, otherwise the stitching software has to change the brightness and contrast of the image between frames and so you get banding in the sky.
Similarly, you should have a consistent focal length (locked focus) for each shot, otherwise the softer parts of the image (perhaps foreground and background) will be inconsistently soft between frames, and so you will get banding from this too.
Now, all of this is not a problem for most people who just want to remember what that great view looked like, and who will only ever print out small prints of it.
A bit of banding in the sky, some funny lines in the foreground detail, etc. won't matter.
If you care abou the detail however, and want a www.kenduncan.com.au result ... a Panoramic Tripod Head is the ONLY way to go.
Ciao for now
Andrew.
FollowupID:
443926