I have been playing with some old (pre-collimation) M42 data to see if my processing has improved and I thought that I would give GraxPert a try (See this month's Astronomy Now).
My very unscientific conclusion is that it is fantastic at removing gradients but it introduces noise.
I was wondering whether anyone who knows what they are doing has any experience of this software?
John
Not heard of it John. So not tried it.