Data at Last! NGC7822

[Icesheet]

I've had the most frustrating winter trying to image. So much so I've threatened to put all my gear up for sale on more than one occasion! Funny how a couple of hours worth of data makes everything in the world right again

 

It's not as much data as I would have liked but here is 1hr 40min of Ha integration on NGC 7822. Captured on the NINA software using a Samyang 135mm at f2 and ZWO ASI 1600mm with 31mm Ha filter. Stacked in DSS and processed in PhotoShop CC

Gain: 200

Offset: 50

Lights: 25x240s

20 calibration frames each of darks, flats and dark flats

 

I'm not the most experienced at processing so I would like some good advice on what I could do better. I'm pretty sure my focus is off, which I expected as I no matter how hard I tried I couldn't get a FWHM lower than 2.5. There is also some black blotchy noise which I can't seem to control as well as I'd like. I'm not sure if 240s exposures were the best idea since it was a 3/4 moon and I was imaging towards a light source even it was behind a hill. 

If anyone would like to have a go the RAW files are here : https://drive.google.com/drive/folders/1XyVwyAEgc674fwjJYCfqAPLW7SEsJAwF?usp=sharing

 

Despite that I'm fairly happy, I can definitely see the skull anyway! Let me know what you think and post your effort if you have the time!

 

EDIT: I see I have forgotten to upload the darks to Google Drive. Will do it when I’m home from work.

 

[Icesheet]

Darks now uploaded for those who are interested!

[jjosefsen]

Glad you stuck with it, that looks great. I've read that it can be hard to focus at F2, so I guess practice makes perfect?

Also shout-out for a fellow NINA users. ?

[Icesheet]

1 hour ago, jjosefsen said:

Glad you stuck with it, that looks great. I've read that it can be hard to focus at F2, so I guess practice makes perfect?

Also shout-out for a fellow NINA users. ?

I was actually just about to pay for the SGP pro license when I came across your post about NINA so thanks! I didn’t do anything fancy with it but it just worked. I don’t usually say that with this hobby! Connected the camera, filter wheel set up a sequence and I was away. I was really impressed with the simplicity and functionality of the user interface. Can’t believe it’s free!

[wornish]

Nice work.  Big thanks for sharing your data.  I certainly need to practice more.

I have downloaded your files and tried processing using APP and PI but I am really struggling to handle the light pollution. Your final image is way better than anything I can do with your data so far, well done.

 

 

 

[tooth_dr]

Thanks for sharing.  I didnt have time to download the data and stack it but I tried to remove the LP gradient from your image:

[Icesheet]

Thanks for looking  @wornish and @tooth_dr. 

 

8 hours ago, tooth_dr said:

Thanks for sharing.  I didnt have time to download the data and stack it but I tried to remove the LP gradient from your image:

That’s a huge difference! It also makes the nebulosity ‘pop’ more. Did you do this in photoshop? I’ll be fiddling a bit more now ?

[wornish]

What a difference with the light pollution removed.  @tooth_dr can you share the steps taken?

 

I had another go stacked in DSS processed in PI then quite a bit in PS.

 

 

[Icesheet]

2 hours ago, wornish said:

What a difference with the light pollution removed.  @tooth_dr can you share the steps taken?

 

I had another go stacked in DSS processed in PI then quite a bit in PS.

 

 

That’s a huge difference too! Great effort. A bit more noisy sure but you’ve got rid of the LP and really brought the nebula out! Would like to know your process too! I knew there would be more that could be done in better hands than me!

[wornish]

1 hour ago, Icesheet said:

That’s a huge difference too! Great effort. A bit more noisy sure but you’ve got rid of the LP and really brought the nebula out! Would like to know your process too! I knew there would be more that could be done in better hands than me!

I did the standard stacking in DSS nothing special.

Then in PI

 First I used Auto Background Extraction which helped remove some of the light pollution but nowhere near all of it, so it still was very noticeable.

Then I used Morphological Transform to slightly reduce the star sizes.

Followed by the  Screen Transfer Function with the Histogram Transform Tool to stretch the image.  I then created a Range Mask to protect the nebula and used the Curves Transform to begin to darken the background.

The pollution was still very visible so I resorted to PS.

Here I simply increased the contrast and applied it using a large soft brush via a layer mask to the regions around the nebula.  I repeated this a few times to try and get the background consistent.

Finally, I used a High Pass filter to sharpen up the image, then resized to finish.

That's it.  

I did have a play with GradientXterminator as well but didn't like the result so abandoned that version.

Thanks again for sharing your data, the more practice I get hopefully I will get better.

 

[Prolifics]

Nice! Great detail and depth! Stars seem to be good too.

[Icesheet]

Much appreciated @wornish! Much of it is over my head at the moment but google is hopeful my friend. I don’t have PI but I think I’ll five the trial version a whirl to see how I get along. I won’t be imaging much up here now anyway.