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Originally Posted by StargazerX1
There is plenty of evidence to suggest that other factors
may also contribute to the onion ring effect. I have experienced
this effect with properly exposed Jupiter images.
One indication that it may be a registration problem is that one can select
the Registax prefilter option (any low pass filter) in the Optimize
(not Stack) stage and they all but disappear. Unfortunately some
detail is also lost when this is done which does not appear to be recoverable in the wavelets (I use dyadic after resampling 1.7-1.8x Mitchell).
I notice this particularly when the 'good' images of the planet seem to
oscillate between an ellipsoid and a more circular shape.
If this is not the case, could it be some kind of aliasing effect from the
Bayer pattern of the color CCD? Has anybody seen these darn onion rings that are doing tri-color imaging?
Glenn
Arizona USA
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Thanks Glenn, good to hear it's not just me experiencing Onioning with good exposure levels. My last two Jupiter posts on this forum being clear examples. I'll have to try the low-pass filter thingy - is there a default on Registax? Can you think of a reason that under-exposure would also contribute?
cheers,