Pixinsight DBE on Images Full Of Nebula

[Singlin]

What is the best method to apply DBE to images with 100% Nebulosity?

[johnrt]

What are you trying to correct? A light pollution gradient, uneven illumination not corrected by flats? Can we see the image you are working on?

It's sometimes better not to apply in these circumstances if you really don't need to, or just a very low number of samples hand placed towards the corners.

[Singlin]

Here is a jpeg version of my croped Ha master sub

[johnrt]

Doesn't look like it needs any DBE to me

[Singlin]

That what I figured.

Thanks.

[sharkmelley]

It's a very interesting question though - I struggle with exactly that issue.  In some images there is an obvious gradient that need to be removed but there are very few areas of background without nebulosity on which to place the sample points.

Mark

[ollypenrice]

Here is a jpeg version of my croped Ha master sub

Trunk_Ha_Croped.jpg

Bad news, I think you're stuffed. No way to use DBE on this.

Good news, You don't need it!

I don't think I've ever used or needed DBE on narrowband. I rarely use it on L. The great need arises in RGB where slight colour imbalances (gradients) are readily visisble. You only need a few markers though five is the smallest number I've tried. (Corners and one middle.) You can cop out and use ABE at the defaults... 

Olly

[harry page]

Hi

I agree with olly that DBE will not improve your image much , but there are plenty of background areas you can

put samples on , you only need 5 or 6 , contrary to a lot of peoples view you can use dbe on lots of nebula  

just be careful with few samples and lower the tolerance as low as possible , not seen many Images I can not use DBE on

Harry

[ollypenrice]

It can be worth looking on the net for good images of the same area to see where 'real' background sky might be.

Olly

[Singlin]

I knew I was "Stuffed"   

I am glad that at least I have the fortune not to need it.   

On my second attempt with my new Ha data I did not apply it.

Newbies like me tend to want to throw everything at it expecting more magic to happen.

Rgds,

Simon

[Singlin]

Harry thanks for your excellent tutorials, without them I would not have purchased Pixinsight.

How about a tutorial on bringing out faint nebula on an image like this one, using DBE too?

I can send you the dropbox link to the Ha master frame if you wish.

Rgds,

Simon