Central Portion of Orion

Check out this Tutorial folks www.rc-astro.com/resources/GradientXTerminator/tutorial.html

Thanks Carl! Works a treat!
Just bought it.

Revised image:
www.astroshot.com/Deep%20Sky/2010-01-05-Orion-V2.jpg

michaeloconnell wrote:

Thanks Carl! Works a treat!
Just bought it.

Revised image:
www.astroshot.com/Deep%20Sky/2010-01-05-Orion-V2.jpg

No problem Michael glad I could help. Have a look here also www.rc-astro.com/resources/GradientXTerminator/tutorial.html There is a big difference in the image well done

Carl.

Thanks Carl.
I notice it needs a bit of care around bright stars.
Tends to put in dark halos, which may need some further localised correction.
Very good all the same.

Michael, Carl

I just did a flip from image to image and the rework is a noticable improvement.

I while ago I did a quick experiment with an image I pulled of the internet with sodium streetlights on the horizon.

I thought to myself that skyglow (now correct me if we're talking different subject) is large scale structure that basically is the size of the FOV (and varying across FOV sometimes in irregular but slowly changing ways) so if I go into fourier space and remove very low frequency information I might be able to reduce the orange glow gradients and reveal a darker smoother background.

I think I used a Butterworth high-pass filter in AIP4WIN - but I suspect doing similar with wavelets might produce similar effect.

I convinced my self that it did reduce the background gradient without any obvious degradation in other areas.
There was stil a halo around lights - but a lot tighter than before.

I've always intended to revisit to see if it aids or hinders photometric measurements in which case it might have scientific use for amateurs.

Only did it once and only as an experiment.

If someone has a gradient and no convenient tool like Photoshop and this add-on it might be worth giving it a shot.

Mark