I was just reading a post in the yahoo toucam users group, and found an interesting article a guy posted relating to "ringing" when doing an avi of Jupiter. He also calls it "onion rings".
I quote his post:
most of the time the onion-ring effect is caused by incorrect capture parameters. The brightness slider has to be set to the absolute middle, since the brightness is calculated into the image by the cam/driver, in the middle position it does nothing to the image. Adjust image brightness by exposure time and gain only!
With increased brightness settings, the chosen gain will be too low to expose the fainter areas around Jupiters edge correctly, the underexposure will result in a poor dynamic range causing the ring effect.
In addition, leave the gamma slider at 0, the Toucam works almost linear with this setting. Higher gamma settings will compress the subtle highlights of Jupiter and result in a loss of detail rendering.

End quote:

Interesting stuff, as I always seem to have a problem with the rendering myself and get the dreaded onion rings at times.
Anyone else have any thoughts on the above.

Cheers.

Peter