NGC 6820 in HaRGB

[KathyNS]

I've been wanting to get a clean shot of this nebula / star-forming region for a while. I shot my standard sequence on it last week, but it was just too hard to process. I thought about adding some data from a few years ago, but then I came to my senses and took my own advice: I shot more data. The long-exposure Ha made the difference.

Orion 200mm f/4 Newtonian
Atik 383L+

8x 600s Ha, 1x1
12x 900s Ha, 1x1
8ea 120s RGB, 2x2

Total exposure: 5.9 hours

[BABOafrica]

Such a subtle capture. Just perfect. I especially like the contrasts.

BABO

[mbocca]

Kathy,

That is a wonderful image. I captured the same target in late August and I could not get anything to really standout. Now, I see you added a three hours at 900 seconds.I was not integrating nearly that long.

I have 36 frames at 300 seconds for Ha 12 at 300 for OIII and and 12 at 300 for SII. Ha had pretty good signal. I was capturing this when the moon was too bright to do RGB, and I never went back to collect that.

Clear skies.
Mike

[KathyNS]

That's a nice image, Mike. This is quite a faint target, though. You have 3 hours of Ha, but in what I would consider short exposures.

I usually shoot 8x 10min (aft f/4) in Ha. That gives me frames that are quite underexposed compared to the broadband filters, but usually enough to work with. But this target, being dimmer than what I usually shoot, had very little dynamic range.

I can tell when I am losing dynamic range when I stretch the histogram to put the peak at 25% and the peak breaks down into individual peaks for the discrete ADU levels. With my usual exposure, I was getting that on this target. I realized that I needed not only more total time, but more time per frame. My guiding has been pretty decent since I got the mount balance dialled in, so I figured I'd go for 12x 15min.

The difference was amazing. I didn't have to do much fiddling to have the contrast jump out at me and say, "I'm done". I have learned to listen to the data when it speaks to me like that.

[Jockinireland]

Thats a great image Kathy.

I've often thought about trying that target but always feel that my DSLR is unlikely to do it justice.

[pakarinen]

That is amazing.

[bobharmony]

Great contrast and color, Kathy. Once again time on target rules!

Bob

[MariusD69]

Wonderful! Great job, Kathy!

[Astrovetteman]

Hey Kathy, that’s simply MARVELOUS!! Excellent details and colors while, as Babi says, subtle....best capture I’ve ever seen of this object!!
Fantastic Image!!
Tom