9 replies to this topic

[HoloTheWolf]

My first try of the combo, SH2-129 Flying Bat and OU-4 Squid Nebula. I think they don't need any introduction.

 

This is by far the most demanding project I've ever done. My f/5.6 optics is a bit slow and Bortle 5/6 skies certainly don't give me a lot of advantage in terms of capturing those elusive photons. I could barely see anything in a single 10 min sub. From reading several CN discussions, I knew that the Squid is extremely faint, but I never realized this animal is so shy that you need tons of subs for it to show up. Luckily, over the past 20 days or so the weather in Northern California was really nice. The cloud coverage was constantly around or below 6-8%, the worst being 12-15%. So apart from a guiding issue I still need to sort out, imaging went pretty smoothly.

 

Processing the data, however, is another story. Even with hundreds of subs, the OIII signal in the master light is mixed with noise. Stretching the Squid without blowing up the noise was really pushing my processing skills to the limit. I ended up using a mask in order to suppress the noise. Not a fan of the approach, but that is the best I can do. Now I realize why people go to dark sites for serious works 

 

All in all, this is a fun project and I certiainly learned a lot from it...

 

R: 10 x 300s

G: 10 x 300s

B: 10 x 300s

Ha: 219 x 300s

OIII: 321 x 300s + 146 x 600s

Total integration time: 71 hrs 50 mins

 

[hornjs]

Wow great result!   Well worth the effort!

[maxsid]

Great! 72 hours. Wow.

[choward94002]

Exceptional work!

[Sacred Heart]

You had 20 days of good weather, I can't remember the last time I had 5 days.

 

Excellent job.   What camera and scope did you use??    Joe

[danny1976]

That looks amazing. Can I ask how you added the OIII data?

[HoloTheWolf]

You had 20 days of good weather, I can't remember the last time I had 5 days.

 

Excellent job.   What camera and scope did you use??    Joe

Thanks Joe. It's ASI294MM Pro and FSQ-85EDX.

[HoloTheWolf]

That looks amazing. Can I ask how you added the OIII data?

Thanks Danny. Just plain Channel Combination: R: Ha, G: OIII, B: OIII.

However, before the combination, I did remove the stars from Ha and OIII in the linear stage.

After star removal, I cloned and stretched the starless OIII until the shape of Squid could be seen clearly.

A GAME mask was then created and convoluted (to smooth out the mask edge) using the stretched OIII.

Next applied Histogram Transformation iteratively to the original OIII a few cycles, keeping the noise level as low as possible.

Then add the GAME mask for the final stretch.

Edited by HoloTheWolf, 05 July 2022 - 07:12 PM.

[unimatrix0]

This is great, and I wish I could go into projects like this. Unfortunately I don't think we had 72hrs of clear skies for the whole year so far on the NorthEast. 

[jpengstrom]

I'd say your time and dedication certainly paid off!  Great job capturing and processing a challenging subject!