Need some help with DBE

[wkrispler]

Hi,

I am currently working on IC447 (example attached). Now I want to do DBE but I am lost because in this image I do
not find any background.

How would you approach DBE in such an image?

Thank you,

Wolfgang

[biosif]

Hi.
In image below you have an example, and i think you can understand the proces to help you.

Iosif.

[wkrispler]

Hi Iosif,

so your recommendation is to use ABE instead of DBE with substraction? According to the Pixinsight documentation ABE should only be used in simple
cases where a lot of background is visible but this is more a complex case...

Background Neutralization etc is clear for me, I have done quite a lot of images already.

My question is refering to DBE or ABE only where to put the samples if no background is visible..

THank you,
Wolfgang

[aworonow]

It appears you have fairly nebula-free sky above center, in the upper-right and upper-left corner regions. You can used the 'symmetry' part of DBE if you assume that the gradients are fairly symmetrical about the center. I've shown one point and its vertical & diagonal equivalents. (See the check marks in the upper area of the DBE control window.) I presume the procedure would take those to symmetrical points and assume the same qualities for them as the initial point in the upper-right quadrant.

Also, note that you can drag the white lines (which define the center of symmetry, etc) around.

Finally, do the background adjustment while the images are linear.

Alex