2,200 light-years away, the North America Nebula is an emission nebula in the constellation Cygnus. Rich in Hydrogen Alpha and Oxygen 3 gases, we’re able to capture its beautiful tones of red/pink (Ha) and Blue/Teal (OIII) with our Triad Filter.
With a wider field telescope, you can see the shape of North America and even the Gulf of Mexico. Perhaps next season, we’ll run a mosaic here to show just how vast and beautiful this region is. It piggybacks right along the edge of the popular Pelican Nebula.
Table of Contents
North America Nebula
Captured with our Telescope in B2 skies
- Esprit 120 w/Apex L reducer
- ASI 2600 MC Pro Camera with Triad Quad Filter
- 360-second exposures * 52 Subs
- EQ6R Mount
NGC 7000 Download
Download the North America Nebula stacks and process your own version of this beautiful nebula in the Cygnus Nebula/Region.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Processing North America Nebula
We’re using PixInsight to process our data today. Because this data is extremely clean from our new dark skies observatory, the amount of work we have to do to really make this beautiful region “pop” is pretty minimal.
Normally, we’d have to crop, deconvolute, denoise and then we’d start seeing some fine details but check this out. Here are our stacked subs with no processing done yet. Just screen stretch in PixInsight
Absolutely thrilled with the data we get with the limited time we have so far. We’re late in the season for capturing Cygnus region nebulas but we’re grabbing an hour or two each night before it gets too low to horizon to share with y’all.
Since our data is so good from the get-go, this will be a rather simple processing guide. We want to be delicate to preserve color, texture, resolution, detail.
From a top view, it doesn’t look like we need to do much on the noise – however, I do like to run EZ denoise to try and smooth out the background. If you zoom in on some of the faint nebulosity, you can see some of the background noise.
Let’s see if we can clean that up. (now that I zoomed in, I see I have some somewhere in the stack with some tracking issues, I may re-blink my stack and re-integrate and update this post with newer data – figure I’ll leave it in the docs so people can see – there is a slight elongation to some stars)
Select your main sub in the drop-down box, and hit “Run EZ Denoise” – this tool will generate all the necessary masks and run denoise for you. Squishing down a rather cumbersome process into an EZ process… so EZ that before I’d avoid it if my image was this clean, to begin with, but now it’s just a matter of giving it a try and seeing if things improve.
With an image this clean, you may have to experiment with TGV settings and MMT Settings so you don’t introduce “glass effect” or “splotches”. Sometimes your nebulosity will look like wax/glass if overly denoised and other times if you capture so much dust, denoising it may try and correct some of the fain stuff into blotchy circles.
Denoise does take a while to run. A fast multi-core computer will help you brute force this. Otherwise, runoff and get some other things done while you want for the denoise to happen.
North America Nebula after denoise
As you can see, zoomed in, we toned down some of the grainy-ness, so i’ll definitely stick with this.
Zoomed back out, I don’t see any aberrations from over correction.
I want to preserve the bi-color image, so we’re going to stretch it with unlinked channels. If you leave the chain-link enabled, you will often get hues of red from Ha, OIII, and SII whereas if you “unlink” the stretch, you will preserve the Ha and OIII – Ha being reds and OIII being teals/greens/blues.
I like to clone off an image when I stretch – that way I leave a copy of the denoised “master” alone and if I blow things up or ruin the image, I just close my clone and re-clone a new one without having to dive around and mess with bouncing through history.
Here I’ve circled the chain link that you do NOT want to be highlighted. Once that is unchecked, drag the triangle from Screen Transfer Function down to HistogramTransformation and this will apply that screen stretch to your image as we see it to the histogram.
Now we want to drag the triangle from the lower left of the HistogramTransformation over to the cloned image to stretch it.
Once you do that, your screen may go white – this is because we have a screen stretch applied and now the image has been stretched
In PixInsight, lets click the monitor with the nuke symbol to remove our screen stretch
Now e can see our image and it’s in the non-linear phase of editing. We’re sticking to EZ-processing here so all we need to do is some Curves to make the colors pop a bit.
Let’s open up the Curves utility and click the circle button to open a preview of our image. This way as you drag the curves around, you can see how the image is altered.
Typically with my Triad data on my 2600MC pro, I like to start with an S-CURVE to drop the brightness down of the background and enhance the brightness of the foreground. Something like this.
Once you have something you find appealing, You once again drag that triangle over to your main image and apply those curves.
After applying the curves, I like to click that little target icon in the lower right-hand corner of the curves screen to re-set it back. Otherwise, you may accidentally re-adjust some prior curves that you want to preserve.
Now let’s re-enable the Preview by clicking that circle icon and select the Saturation curves
There is no wrong way to process these images. I find sometimes I like to preserve the green tones so I won’t stretch the saturation as much – but in this image, I found I highlighted very diffuse clouds reflecting light over the very dark clouds, and I kind of like that. So we’ll continue with that.
All in all, I think I could just stare and marvel at this all night long.
So really, for now, That’s a wrap.
Other processing tips
Some people don’t seem to like the greenish star colors. There are several ways to change this. You can shoot RGB of this area and load up the RGB stars. You can Starnet and create a star mask to try and alter the color of the stars or run SCNR on them to remove the blue/green color. I found I like to leave it “as is” since SCNR can reduce the OIII signal that is in the same spectrum and if you ask me – stars passing through rich/dense OIII fields are just brightening up natural colors anyway, so my point is – enjoy and experiment. Blue stars shining through that much Oxygen 3 will appear blue 🙂
BTW, If you run Starnet you can get a beautiful starless image too! Always clone off your image when you run StarNet so you don’t remove stars from your working image 🙂
Beyond going starless, you can also use the star mask and EZ Star Reduction to diminish the stars a tad to focus on the nebulosity, but preserve the star field for something like this.
The image on the right is the reduced star one. Side by side not terribly much different, just the stars are toned down. You can experiment with this since in some images it really tones the stars down.
I don’t mind keeping the stars. It gives me a sense of perspective and awe for just how vast and dense these regions are.
Starless North America Nebula
Always love sharing these, just so you can see the sheer amount of nebulosity in the region!
I find with great data, less is more. We love seeing what readers have done. If you process our data, let us know! Share your links/images/edits/revisions or let us know how you incorporated our data into one of your projects!