Quote:
Originally Posted by skwinty
Well Jase, in your own words "hard pushed" and in my case "being forcefully led" 
Seriously though, I wouldnt have noticed as I am no expert.  |
You didn't read my full statement - "hard pushed to discover uneven field illumination in this image due to the globular". This is technically accurate as vignetting, should it be present has the potential to be masked by the globular structure.
I'm no expert either, but I do know a thing or two. So here is a tip for you (et al). A method to validate data quality is to use the PS equalise function. It is a very good tool to check for background colour gradients. I've have attached a result of the output below. Clearly seen is the donut top left and the red shift/gradient from left to right (as per my comments).
My apologies Peter for making an example out of this image, however it serves as a good educational exhibit.