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M31 HaRGB with RASA 8


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M31 was the object for my first light with the RASA 8 and ASI2600MC back in August. Last night I finally got around to collect some Ha for it. Collected with a dual band filter (IDAS NBX) but I only used the red (Ha) channel. The data was added to the red channel in the RGB image as blend mode Lighten in PS. I think that the Ha clearly lifted the colours of the galaxy in a pleasing way.

For the RGB data I have tried to tame the enormous dynamic range of this object so I could both bring out the outer dust "cloud" (presumambly made up my stars) that is often missed (or outside the FOV) as well as the details in the very bright core that is easily blown out.

Data: RGB was collected without filter as a mix of 10 - 60 s exposures at gain 0 and 100, totally 2.7 hours. Ha was collected over 1 hour as 4 min exposures at gain 100. Stacked in PI and processed mainly in PS. Total integration time was 3.7 hours.

I also include the RGB image for comparison.

 

 

 

20200815 M31 RASA Gain0+100 PS23smallSign.jpg

20200815 M31 RASA Gain0+100 PS16smallSign.jpg

Edited by gorann
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M31 was the object for my first light with the RASA 8 and ASI2600MC back in August. Last night I finally got around to collect some Ha for it. Collected with a dual band filter (IDAS NBX) but I only u

Another superb Andromeda Galaxy,  you keep on posting these, but they can't be as much fun as a 12 panel mosaic...

Thanks Dave! Yes, this was the first light with the RASA so I had not realized I needed to organize the camera cables in a circle, they were just randomly organzed. Now when they are in a circle I get

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32 minutes ago, Adreneline said:

Both are amazing images and a joy to look at Göran.

Thanks for sharing.

Adrian

 

25 minutes ago, callisto said:

I echo that 👍

 

Mark

Thank you both, much appreciated!

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4 minutes ago, peter shah said:

Thats a bit special Goran beautifully processed..... how deep will that RASA go!

Thanks a lot Peter! The depth remains to be seen😁 I should do a whole nighter with it soon when the moon is gone and the nights are long.

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31 minutes ago, Sunshine said:

This is a stunning image of M31, worthy of a wall mount.

Thanks  a lot! Yes maybe I should print it. Haven't done that in many years.

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2 minutes ago, tomato said:

Another superb Andromeda Galaxy,  you keep on posting these, but they can't be as much fun as a 12 panel mosaic...:blink:

Thanks Steve! We both have Esprits and we both have RASAs, and one scope will excel over the other when it comes to targets. With my Bortle 2-3 sky (when the moon is gone) the Esprit 150 will certainly dig out more details on a steady night, but it takes a hell of a lot more time😉. By the way I really enjoyed seeing your Star GaZine talk. A great story with a very happy, and still happening, ending! I wonder if I ever had the stamina to do manual guiding.

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Yes, galaxy season is just around the corner and the Esprits are about to come out of hibernation. 

Thanks for comment on the talk, for sure there is a lot of complication and processes involved with digital AP, but  I wouldn’t want to go back to to the emulsion film days for all the clear nights in Atacama.

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9 hours ago, gorann said:

RGB was collected without filter as a mix of 10 - 60 s exposures at gain 0 and 100, totally 2.7 hours.

Both those M31 images are amazing Goran but the Ha really lifts it.

I think maybe I’m going wrong and overexposing.  I was shooting 300s at gain 100 at F4.4 

Edited by tooth_dr
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Really superb, and you've just answered a question I asked you on another thread regarding the combining of filtered and unfiltered OSC data.  I like everything about this image, from the faint outer halo to the excellent core, all done without it looking forced. That's the natural field of the RASA and your camera? Pretty wide. I have to say it, though: you've cropped off that upturned extension on the galaxy's left side: you know you can't sleep till you pull it in with a second panel! :D

The stars are also excellent. Your rig works. I can feel the sweet tug of temptation...

Olly

Edited by ollypenrice
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Thanks Olly! You are too kind! I just answered your question on the other post before I saw this. Yes, that is the full FOV of the set-up. No calibration frames used whatsoever, just a bit of Gradient Exterminator that easily fixed the slightly darker corners. That second panel is going to make an interesting CinemaScope framing with a lot of space to the left😉

440px-CinemaScopeHighandMightyTrailerScreenshot1954.jpg.b8a861e3d878e7b912be14dc6a5dc9b7.jpg

This is what the 1 hour HaOiii image looks like - quite interesting on its own.

20210131 M31 NBX RASA PS7.jpg

Edited by gorann
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11 hours ago, tooth_dr said:

Both those M31 images are amazing Goran but the Ha really lifts it.

I think maybe I’m going wrong and overexposing.  I was shooting 300s at gain 100 at F4.4 

Thanks Adam! For the RGB I used a mix of 60 s at gain 0 and 30 s at gain 100. (I was testing out the effect of gain since this was first light). So quite short exposures and I think that is what saved the core. I also took 50 x 10 s at gain 0 but I do not think I needed them or used them.

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Very nice Goran, the Ha really lifts it..   Do you know what's causing the Bhatinov Mask like spikes on some of your brighter stars?  @tooth_dr had similar on one of his recent images taken with the same camera

Dave

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1 hour ago, Laurin Dave said:

Very nice Goran, the Ha really lifts it..   Do you know what's causing the Bhatinov Mask like spikes on some of your brighter stars?  @tooth_dr had similar on one of his recent images taken with the same camera

Dave

Thanks Dave! Yes, this was the first light with the RASA so I had not realized I needed to organize the camera cables in a circle, they were just randomly organzed. Now when they are in a circle I get no spikes.

Edited by gorann
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34 minutes ago, Nigeyboy said:

Speechless . . . . . stunning doesn't quite cover it. 

👏

That is a bit over the top😁 Thank you very much!

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9 hours ago, gorann said:

Thanks Olly! You are too kind! I just answered your question on the other post before I saw this. Yes, that is the full FOV of the set-up. No calibration frames used whatsoever, just a bit of Gradient Exterminator that easily fixed the slightly darker corners. That second panel is going to make an interesting CinemaScope framing with a lot of space to the left😉

440px-CinemaScopeHighandMightyTrailerScreenshot1954.jpg.b8a861e3d878e7b912be14dc6a5dc9b7.jpg

This is what the 1 hour HaOiii image looks like - quite interesting on its own.

20210131 M31 NBX RASA PS7.jpg

My, you must have quite a sky, that NB image looks like one of my LRGB efforts on a good night!

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52 minutes ago, tomato said:

My, you must have quite a sky, that NB image looks like one of my LRGB efforts on a good night!

On a really good night I can have the SQM meter showing 21.6 (Bortle 2-3), but most often around  21.2, so yes I am in a rather dark patch. That image was taken between 7 and 8 pm two nights ago before the moon started rising and I could see the subs getting brighter and contrast going down. That is why I only used the first hour of data and thought it was good enough at f/2 for adding some Ha to my RGB data. I did give it a good Gaussian blur bifore I added it to the red channel so it would not introduce noise.

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Wow.. amazing stuff. Who would have thought not that long ago OSC (in the right hands of course) would be this good!..  You do realise that you've single handedly, with your constantly amazing posts, persuaded me to order a OSC ASI2600 for galaxy season!!.. shame on you 🤣😉

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3 hours ago, Sp@ce_d said:

Wow.. amazing stuff. Who would have thought not that long ago OSC (in the right hands of course) would be this good!..  You do realise that you've single handedly, with your constantly amazing posts, persuaded me to order a OSC ASI2600 for galaxy season!!.. shame on you 🤣😉

Good choice and you will not be dissapointed! I just put my ASI071 OSC on my 14" Meade ACF to be ready for galaxy season in Obsy 2. Although it is clear tonight, seeing is not good enough for 3.5 m FL tonight so I am just running the RASA with the ASI2600MC in Obsy 3 - a very forgivable set up.

Edited by gorann
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