NGC 7023 Gradient Problem

[Solidarity]

Hello PI User,

I have a gradient problem and need help to reduce it. i tried ABE and DBE but I am not satisfied. It's a 6 hour Iris widefield with ED80 at 510mm on NEQ3. EOS 400 D astro 600 sec exposure time.

https://www.dropbox.com/s/gjbidu4tkou8h09/NGC7023.tif

Hope anybody can help me.

CS

Karsten

[Harry page]

hi

I am sure we can help    do you have a version you have not stretched as DBE should be used on a linear image


Harry

[Solidarity]

Hello harry,

that will be great  And I am sure you can.

Here I have the fit file for you.

https://www.dropbox.com/s/uqblflx33usx1z1/NGC7023lineargradient.fit

Thanks a lot

Karsten (from cloudy germany)

[Harry page]

Hi

Lots of colours there 

Up the tolerance a bit and you are on a winner 

DBE settings in the ZIP file

Regards

Harry

[Solidarity]

Hello Harry,

fantastic!!! 

It worked very well on that coloured image. I don't know why theres such an incredible gradient in it.

Thanks a lot and In will show you the processed image soon (I am very busy at the moment and it will work slow)

Greetings and CS

Karsten

[Solidarity]

Hello Harry,

I did a new integration of the image and now I have the same problem. My result is not as good as yours. Can you please help me another time to see what i am doing wrong. I will compare your solution with my try.

https://www.dropbox.com/s/dvemwoirwqc1nba/IntegrationNGC7023.fit

Thanks a lot!

Karsten

[Harry page]

Hi

Well I see why you are struggling 

There is a massive red bias which I can not get DBE or background neutralization to correct ( perhaps due to the high noise )

I could only correct the bias manually or the easiest way is to unlink the channels on the stf and transfer this setting to the histogram tool .

I am sorry I do not have a quick answer and will keep trying and get back to you

Harry