LRGBHa M31 Andromeda Galaxy (the Andromeda Galaxy)

 Posted: Sep 27th, 2026
Technical Info
Telescope/Lens: Askar FRA500
Camera: ZWO ASI2600MM PRO
Mount: Sky-Watcher EQ6-R PRO
Guide Scope: ZWO OAG-L
Guide Camera: ZWO ASI220MM
Software: PixInsight, RC-Astro plugins
Accessories: Sharpstar Focal Reducer 0.7x ASKAR FRA 400 / 500
Exposure:
210 x 120" ISO/Gain: 100 - Antlia V Pro L
113 x 120" ISO/Gain: 100 - Antlia V Pro R
113 x 120" ISO/Gain: 100 - Antlia V Pro G
117 x 120" ISO/Gain: 100 - Antlia V Pro B
67 x 600" ISO/Gain: 100 - Antlia H-a 3nm
125 x 1000" ISO/Gain: 100 - Antlia H-a 3nm (Krasnodar)
 Mezmay Solnechnyy Veter, Россия
 Aug 13th, 2026
64 h 19 m
336
Resolution: 6114x4035 px
Scale: 42426 KB

Here you can see the correct addition of hydrogen. There is exactly as much of it here as there should be.
The hydrogen is aligned to the red channel. Then it is stretched in the same way (as the red channel) and added to the red channel of the LRGB image. Of course, after continuum subtraction. I subtracted the continuum manually and added the hydrogen to the red 1 to 1. Without any masks, boost, frasold, or hydrogen contrast. No personal taste, only pure math.

Yes, this is what 46 hours of hydrogen looks like. For the sake of beauty, I would like to pull out more "background" hydrogen, but I did not do this in favor of naturalness.
It is also worth noting that I accumulated a significant portion of the hydrogen under urban light pollution, shooting right from the loggia for almost the entire month) These almost 35 hours of accumulation are inferior to 11 hours of accumulation in Mezmay. Just imagine, the accumulation is 3 times less, but at the same time the noise is 17% lower. This shows that accumulation is not the same as accumulation, if they are collected under different light pollution conditions, even despite a narrow passband of only 3nm! I am also not sure that I integrated the Krasnodar accumulation into the Mezmay one correctly, but the noise decreased by 1.5 percent. I still did not understand by how much the SNR increased. I did not even notice the difference visually. Therefore, perhaps I will return to the hydrogen accumulation and reprocess it, also making an artistic version of the work (with an abundance of hydrogen in the background).

Just for those who want to see hydrogen by itself, I will upload two more images.

Updated
  27 Sep, 2026
  64 h 19 m
Version without stars so that the natural integration of hydrogen can be seen.
Current photo
  27 Sep, 2026
  64 h 19 m
Here you can see the correct addition of hydrogen. There is exactly as much of it here as there should be.The hydrogen is aligned to the red channel. Then it is…
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Cool
27 Sep, 2026 Reply
For 46 hours, that's pretty weak.
28 Sep, 2026 Reply
Oeswww Replied to Iren
This is not an artistic version. Everything here is according to the finish (see the description and this https://deepskyhosting.com/w94pCpu) :)
28 Sep, 2026 Reply
Iren Replied to Oeswww
Well, a lot also depends on the level of light pollution. With a pixel, you can bring out hydrogen well.
28 Sep, 2026 Reply
Oeswww Replied to Iren
I wrote about light pollution to convey that accumulation in different Bortles is not equivalent. That is, hours of accumulation in Krasnodar are many, but the result is not even comparable to a small accumulation in Mezmay =) That's the first thing. Also, one should not forget about the speed of accumulation (focal ratio). That is, we already have two variables that make accumulation time insignificant and not reflecting the real picture of signal) Yes, it is a simple indicator for estimating the volume of accumulation, but it is still relative to the same equipment in the same shooting zone.

On the other side of the coin is the faint hydrogen background, which also creates false impressions of low accumulation. But it is simply like that by nature. Therefore, it is not objective to evaluate hours/quality of accumulation by the faint background) Here it is already a matter of taste, but in this case I did it as it actually is :)

In general, I myself am also a fan of "picture" and "artistics" and therefore I will also stretch the background for beauty and publish it on AstroBin. I did not get fancy with stretching at all. Everything was aligned by signal relative to each other and stretched identically. I did not even want to make the core fainter, because it looked natural and very smooth and the point in the center did not stand out at all (I did not want to do 60-second subs and therefore the core is minimal, but it burned out), but in this light pollution there was still a bit of structure and I only slightly applied HDR to the core to reveal it. In short, everything is as close to natural as possible =) I did not even embellish the oxygen in the galaxy separately and it remained as it is.
28 Sep, 2026 Reply
Impressive) how long did you accumulate the signal for?)
6 Oct, 2026 Reply
Oeswww Replied to Alena Kiseleva Beautys89
The Krasnodar hydrogen was accumulated over a month, 2-3 hours at a time, but for some reason it doesn't seem to add much. The rest was captured during a one-week astro trip (about 19 hours).
6 Oct, 2026 Reply
Great! I don't know if I'll ever get around to deep-sky...
6 Oct, 2026 Reply
Oeswww Replied to Sabotajnik_ru
They will arrive. And I, on the contrary, now want to shoot a planet)
8 Oct, 2026 Reply
Sabotajnik_ru Replied to Oeswww
I wonder what the "planetary" seeing is like in the Mezmay - Guamka area... There's little light pollution there, but it hardly bothers planets anyway. The main thing is atmospheric steadiness.
8 Oct, 2026 Reply
Oeswww Replied to Sabotajnik_ru
That's right. That's exactly what I want to check. But from what I can tell, judging by deep-sky, it's not much better. And you also have to wait for suitable conditions.) From the yard, it's probably easier to catch them.
8 Oct, 2026 Reply
Sabotajnik_ru Replied to Oeswww
Need a large and fast SSD. Speed no lower than 1000MB/s, only honest ones. Capacity no less than 1TB.
8 Oct, 2026 Reply

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