DBE--PLESAE HELP

[rdryfoos]

This keeps coming up and I have not been able to find the answer,  So please, will the designers of DBE chime in.  When there is no background, as in the attached image.  Where to place the points--in the darkest areas?, in the least dense areas, no DBE, only ABE?  What is the correct procedure?

Thanks,
Rodd

This image has only  a touch of Mure Denoise, cropped edges and an STF stretch

[bob_franke]

This keeps coming up and I have not been able to find the answer,  So please, will the designers of DBE chime in.  When there is no background, as in the attached image.  Where to place the points--in the darkest areas?, in the least dense areas, no DBE, only ABE?  What is the correct procedure?

Hi Rodd,

I know this is not the answer you want, but there really isn't much you can do with this. I compared your field of view to a POSS2 red image and yours looks good as is. I think any attempt with DBE or ABE will do more harm than good.

Here's a link that will create a webpage with a POSS2 red image of your FOV. The webpage will have of FITS link that you can download into PI.
https://skyview.gsfc.nasa.gov/current/cgi/runquery.pl?coordinates=J2000.0&SURVEY=DSS2+Red&Position=0.5592+67.1888&pixels=2000,1514&Size=1.0222,0.7738&Rotation=-181

It as been suggested that it may be possible to create a generic background model for a specific area of the sky. This would likely be very difficult. Several factors can affect the results. The time that the image is acquired, the position of the moon and weekdays versus weekends, plus more that I haven't thought of.

You can also try doing this on the fly. Halfway through a group of exposures, you can slew to nearby clear starfield and take a couple quick images to get a background model.

Now here's a challenge.
Can anyone think of a way to use a sky survey image as a reference for LocalNormalization?

Cheers,
Bob

[rdryfoos]

This keeps coming up and I have not been able to find the answer,  So please, will the designers of DBE chime in.  When there is no background, as in the attached image.  Where to place the points--in the darkest areas?, in the least dense areas, no DBE, only ABE?  What is the correct procedure?

Hi Rodd,

I know this is not the answer you want, but there really isn't much you can do with this. I compared your field of view to a POSS2 red image and yours looks good as is. I think any attempt with DBE or ABE will do more harm than good.

Thanks Bob--But what happens when there is a gradient in the image?  This is Ha--but what about RGB or Lum?  I have shot image slike that, hardly any background but a gradient none the less.
Rodd

Here's a link that will create a webpage with a POSS2 red image of your FOV. The webpage will have of FITS link that you can download into PI.
https://skyview.gsfc.nasa.gov/current/cgi/runquery.pl?coordinates=J2000.0&SURVEY=DSS2+Red&Position=0.5592+67.1888&pixels=2000,1514&Size=1.0222,0.7738&Rotation=-181

It as been suggested that it may be possible to create a generic background model for a specific area of the sky. This would likely be very difficult. Several factors can affect the results. The time that the image is acquired, the position of the moon and weekdays versus weekends, plus more that I haven't thought of.

You can also try doing this on the fly. Halfway through a group of exposures, you can slew to nearby clear starfield and take a couple quick images to get a background model.

Now here's a challenge.
Can anyone think of a way to use a sky survey image as a reference for LocalNormalization?

Cheers,
Bob