New Gradient removal technique By Vicent Peris - Forums

Topic starter

Apr 25, 2020 · Edited: Apr 25, 2020

Hi all,
in the last few nights I have tested the new technique of gradient modeling and removal by Vicent Peris (https://www.pixinsight.com/tutorials/multiscale-gradient-correction/).
In my opinon works very well.
in my two latest images you can see the results.

In M101 you can also see a comparison between before and after the correction.

Oleg Zaharciuc

Apr 25, 2020

Nice, thanks!

Jerry Yesavage

Apr 25, 2020

Hi, went back and read the technique, looks like you need to have a second image that overlaps the first… a bit too much for me without an operational second camera… but I have been thinking of adding one of the newer CMOS cameras atop my main telescope for wide angle… maybe this is an excuse.

I have the same gradients you have and maybe will post them when I put up M 53, which I am working on today while house-bound.

Edoardo Luca Radice (Astroedo)

Topic starter

Apr 26, 2020 · Edited: Apr 26, 2020

looks like you need to have a second image that overlaps the first…

That's right: you need a secon wide field image to use as a reference for the primary.

As a secondary camera I'm using a Canon 60D with a 180 mm telephoto lens by Leitz (an Elamerit-R 180 f/2.8 ).
I control the camera only with the intervallometer.

Alberto Ibañez

Dec 14, 2020

Hi, went back and read the technique, looks like you need to have a second image that overlaps the first... a bit too much for me without an operational second camera...

Just for your reference, I tried this technique with a reference taken from the web (aka not mine) and worked surprisingly well… I must do an in deep analisys, but seems that it is not mandatory to gather your own data to apply this technique.

Richard Francis

Jun 20, 2021

Thanks for pointing to this tutorial. With an additional wide-field imager, or indeed an on-line image source, it looks very useful for LRGB images. However, I fear that for narrow-band it could be a bit more tricky. Self-captured wide-field images could be possible with 2 sets of narrow band filters with the same passbands, but on-line sources are more difficult as we need access to the individual channels to make sure that the channel combination is the same.

cheers,
Richard

Well Written Insightful Respectful Concise