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Anonymous
| | Posted on Tuesday, October 26, 1999 - 11:19 am: |   |
We use a 15mm lens, many of the spaces we photograph have high ceilings. At one time we would take 24 pics for a 360, on the advice of the people who did our stitching for us, they said you get a smoother transition from frame to frame??? |
John Strait
| | Posted on Tuesday, October 26, 1999 - 11:47 am: | |
For 35mm cameras, the angle covered is given by:
q = 2 * arctan(12 / focallength) (portrait)
q = 2 * arctan(18 / focallength) (landscape)
For k% overlap, the number of images needed is given by:
n = ceiling(360 / ((100 - k) * q / 100))
More overlap helps avoid problems from inaccurate focal length settings since the warping is minimized in the center of the image. More overlap allows you to only use a small section from the middle of each image where the warp has the least effect.
More than 50% overlap doesn't really help in The Panorama Factory. I recommend 20-40% overlap, but you should experiment and find out what works best for you.
Lots of overlap is especially useful if you are stitching ordinary photos (i.e. not swing lens or rotational) without warping. It might be a reasonable approach with 24 pics at 15mm. That's an average of 15 degrees per image. A 15mm lens on a 35mm camera in portrait mode covers 77 degrees. That's an overlap of 80%!
For 20% overlap with a 15mm lens you only need about 6 images in portrait orientation.
Rectilinear wide angle lenses tend to have more distortion. And the warping creates a scalloping effect at the tops and bottoms of the image. More images reduces the scalloping and mitigates the distortion by making the image sides less significant.
And fewer images will certainly make things go faster! |
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