StarTools

On another forum an experienced imager has posted an LRGB image that he is not satisfied with.

He has put the individual stacks on dropbox and invited others to process them to see if they can improve on his work.

While I wait to get some worthwhile data of my own, I thought I would try his, but when I get to the wipe module with Autodev selected I get a really strange effect: The datasets are here:
https://www.dropbox.com/s/7xdgm7tdp3b79ak/BLUE 1333_reg_cp.tif?dl=0
https://www.dropbox.com/s/thlsp8yoqlgovjp/GREEN 1333_reg_cp.tif?dl=0
https://www.dropbox.com/s/gy49ofzj2daemhf/RED 1333_reg_cp.tif?dl=0
https://www.dropbox.com/s/1470o2c1674t84l/LUM 1333_reg_cp.tif?dl=0

and the whole discussion thread is here
https://stargazerslounge.com/topic/2796 ... 33/?page=1

My question is what should I do to get StarTools to process this data? Others are managing it, albeit with different software.

It needed cropping before doing anything else, there were stacking artifacts and they cause this effect.

ChrisH

How much did you have to crop it by, Chris?

Even a fairly hefty 100 px per side crop doesn't get rid of the effect and the owner (who is a pretty experienced astro imager) has already cropped it (according to post 20 in the linked thread).

almcl wrote:How much did you have to crop it by, Chris?

Even a fairly hefty 100 px per side crop doesn't get rid of the effect and the owner (who is a pretty experienced astro imager) has already cropped it (according to post 20 in the linked thread).

Best to use AutoDevelop first and look critically at the edges, if you see stacking artifacts (sharply defined dark/light borders) then you must crop them off. Any dark borders will cause this effect because Wipe will try to compensate for them (include the dark edges in its estimation of the gradients). To get the effect you have there all 4 sides must be affected. You might also try to use the 'vignetting' option instead of the normal wipe because that expects dark edges and uses a different algorithm to cope with them, but if there are sharply defined borders then even this will not work well. In either case you need to play around with the parameters for optimal correction, but only experience will tell you what to set these at with any particualr image.

ChrisH