DBE with fixed sample values? Anyone uses it?

[Alberto.I]

Dear all,

I've been investigating the different parameters that offers DBE and realized that the sample values can be fixed. I found it very interesting to fix gradients in images with images where the nebulas fills the entire FOV.
What I did is to put the same values to all the samples (so a flat syntethic backgroung is generated) and then tweak the values to compensate the gradients.
I'm considering to wirte an tutorial about this methodology, but I wolud like to learn more about this procedure.

So, does anyone use this DBE on this way? and/or do you know where can I find more information regarding this subject?
I'm specially interested in to be able to calculate the exact values needed to achieve a specific value on the corrected image.

Best Regards.

Alberto.

[ngc1535]

Yes, I use fixed values for samples... especially as tool for fine-tune symmetries found in the data. For example, vignetting is typically circularly symmetric and just a few well placed rings will characterize the effect that needs to be corrected. However, one ring might just over/undercorrected... so putting a fixed sample and fine tuning the calculated value can be very powerful.
You can see an example with my free content here:  https://www.adamblockstudios.com/categories/Free_Content  (the first video on the page).
-adam
 

[Alberto.I]

Hello Adam,

Thank you so much for the reply and the info!
I've watched your video and saw your approach. I used this relative tweaking also, but I understand that may be possible to calculate the absolute values needed to achieve a desired background level for a given sample, or even better, to achieve a desired color balance, don't you think?

I will investigate more about this workflow. I think that could be very useful for fix images with "rainbow" gradients...

Best Regards.

Alberto

[STEVE333]

Yes, I use fixed values for samples... especially as tool for fine-tune symmetries found in the data. For example, vignetting is typically circularly symmetric and just a few well placed rings will characterize the effect that needs to be corrected. However, one ring might just over/undercorrected... so putting a fixed sample and fine tuning the calculated value can be very powerful.
You can see an example with my free content here:  https://www.adamblockstudios.com/categories/Free_Content  (the first video on the page).
-adam

Thanks Alberto for posing the question and Adam for reminding us of the link to your tutorial.

Steve