|Posted on Wednesday, May 30, 2001 - 8:06 am: |
Yesterday, I tried to merge 5 fotos from the mountains for the first time using V1.6, photographed with a 28 mm focal length camera. It was very nice and simple, and merging was really surprisingly perfect. But: all seams show a
continuous vertical band, where the colours are more saturated, e.g. sky, snow, ground.
What is the reason (are pictures not uniformly exposed at the edges?) or can I adjust this in the software?
Best regards Gerhard
|Posted on Wednesday, May 30, 2001 - 8:32 am: |
Sometimes this is caused by brightness "fall-off"
in the corners of the imported images. The fall-off can be caused by vignetting or just by the nature of your lens design. In simple lenses, brightness falls-off by the fourth power of the cosine of the angle away from the center. Lens designs compensate for that fall-off, but sometimes the compensation is not completely successful.
The fall-off is generally more pronounced in the corners of the images and tends to show more with smaller overlaps. Overlaps approaching 50% don't really show the effect.
Elsewhere I recommend 20-40% overlap. If you suspect that your overlaps are darker because of brightness fall-off, it may help to increase the amount of overlap.
|Posted on Wednesday, July 18, 2001 - 12:38 pm: |
Is the fall-off that you mentioned what is visible in this pano:
I have been trying to stitch a beach scene using 6 digital camera photos and I am getting similar banding results in the overlap sections.
|Posted on Wednesday, September 28, 2005 - 1:25 pm: |
Yes, I have fallen into the same trap (again) and stitched up a nice 'zebra' - see attachment. This is despite using the correction for fall-off in the PF 3.4 and the fact that I was using a long telephoto lens. Is there any way to correct or at least reduce this effect by tuning the SW blending properties? Irrespective of this PF is a great product, John!