So, Bostronomy and I did a thing! After the recent APOD winner that featured the Crescent Nebula as a collaboration between three individuals, we decided to take our data on the same target and see if we could combine them. It began more as a test – we did not set out to do this when we first gathered data on the target – and only I had calibration files for my light frames, but I took our data, ran it through Astro Pixel Processor and behold, we were able to combine our data and process it!
Above, we have that data processed without simulating a luminance layer.
61 x 420s – Meade Series 6000 80mm Triplet APO Refractor Canon EOS Ra Ho-Tech Field Flattener Optolong L-eNhanced Filter
Full calibration frames – dark, flat, dark flat and bias frames. Data taken over 3 nights.
50 x 300s Explore Scientific ED102 ZWO ASI 2600mc-Pro Ho-Tech Field Flattener Optolong L-eNhanced filter
No calibration frames…
I stacked the images in Astro Pixel Processor, letting it know that the images were shot at different focal lengths and with different optics. I used different LNC and Multi-band blending settings to see what ended up the best (in my opinion) – This image was done with a LNC setting of 2nd degree and 6 iterations. From there, I let APP do a stretch, normalize the background and I did a light pollution removal. From there I took it in to Photoshop. In Photoshop, GradientXTerminator was used on its lowest settings with no background calibration. Starnet was not used. Astronomy Tools Actions used to remove noise (Deep Space Noise Removal) and to make stars smaller. No sharpening. Most processing was done in Camera RAW filter to set Vibrance & Saturation. The black, white, shadow and highlight were also used, as well as some minor contrast and exposure changes. Color mixer (in RAW Filter) was used to lightly boost red and blue saturation. For the starless, I did put it in starnet. For the inverted, I simply used Photoshop
The only difference here is that I took the red channel from the starless image in the first group and added that as a slight luminance layer. I set it at 5% opacity and adjusted the curves a little bit to try and bring out a little more nebulosity. The downside with doing it this was is that it can make it appear a little more pinkish then intended.
As mentioned before, this wasn’t planned at all, so we are hoping with doing an actual plan we will be able to produce something a lot better! Stay tuned!
I normally don’t do this – I typically leave my reprocesses to either Twitter or Instagram – but in this case, because I feel like this reprocessing of data added a lot more to it, I decided to make a post. Over the past several months my image processing has evolved to a place where I feel it is a lot better then it was back in January when I first took these images and put them together. I decided to go back and stack them all from scratch and start the process over. Below is the result of that effort.
This is a total of 11.5 hours over six individual sessions. I am looking forward to shooting this again when it is up and available for me, but probably in a slightly shorter focal length. This was shot at 380mm and I want to shoot it at 275mm with my Radian Raptor 61.
L-eNhanced: Jan. 7, 2021 – 40 x 240s (800 ISO) Jan. 10, 2021 – 40 x 240s (800 ISO) Jan. 20, 2021 – 19 x 240s (800 ISO) Jan. 21, 2021 – 37 x 240s (800 ISO) Jan. 22, 2021 – 23 x 240s (800 ISO)
NGC 6888, known as the Crescent Nebula (or Brain Nebula in some circles), is located around 5000 light years away in the constellation Cygnus. Close to the star Sadr, NGC 6888 is an emission nebula that was discovered by William Herschel in 1792.
I didn’t start out planning to shoot this target, but after putting my new Radian Raptor 61 through its first light paces, and capturing it in the corner of gathering light on Sadr (see this post) and the nebulosity around it, I decided to hop back to the Meade 80mm and try to shoot it at a longer focal length. Along with the Crescent Nebula, I also put a focus on Western Veil (seen in my previous post) and I am now putting a focus on Eastern Veil. Going from wide field to a slightly smaller field of view can be very fun, especially when you start to make out detail in some of the smaller objects.
I was able to get just over seven hours of total integration over 3 different nights. The first two nights the moon was not really present and it it wasn’t too bright when it was. The final night the moon was around 80% luminosity and up the entire imaging session. For all three sessions I used the L-eNhanced filter by Optolong filters. This filter is great for isolating the Ha and Oiii wavelengths of light as well as suppressing the light pollution that surrounds me – especially under Bortle 8 skies here in Rhode Island.
Equipment & Image Information
Meade Series 6000 80mm Triplet Refractor Canon EOS Ra Ho-Tech Field Flattener Optolong L-eNhanced Filter Sky Watcher EQ6-R Pro Mount ZWO 30mm f4 MiniScope (guide) ZWO asi120mm-mini (guide) Pegasus Power Box Advanced
I have been asked a few times recently about how I process my images. First, the two people I have gleamed the most information from are AstroBackyard and A.V. Astronomy. Both Trevor and Aaron provide wonderful tutorials and resources on just about everything you need when it comes to astrophotography, and I would encourage you to go and follow these two. That being said, my processing is not perfect, and in some cases probably comes off as lazy, but in the end, I am happy with my images and in my opinion, that is the most important thing there is. Obviously, improvement can always come and should be welcome, but being happy with your product is the first key to success.
I begin by stacking in DeepSkyStacker. Even though I use DSLR which is non-cooled, I still take dark and bias frames. I also take flats and dark flats. Because my camera is not cooled, I take dark frames right before I begin my imaging session. I could go through and do an average sensor temp with my dark frames that relate to the sub frames I take, but I do not. I try to take 10-20 dark frames, 50 bias and either 25 or 50 flats and dark flats.
Once stacked, I bring them to Photoshop where I do the majority, if not all, of my processing. My typical work flow is the following: – Small crop, convert to 16bit image from 32bit – Initial leveling – Threshold layer to find dark and light points – Levels – each channel separate to bring them in line – Curves – slight curve adjustment, then quick leveling (each channel individual) and repeat until my black point reaches around 36 in each channel – GradientXTreme – Usually on the two lowest settings, never higher then the middle setting. I look at it both with leveling background checked and without – Astronomy Tools Actions – I usually run the two Violet Halos options as well as Smaller Stars here – Camera RAW Filter – Here is do a lot, especially on my first go through – First, I look at the Color Mixer and adjust individual saturation and luminance. Usually it is red and orange channels, and sometimes the aqua and blue channels. I then go to the Basic tab and adjust vibrance, saturation, black, white, highlights and shadow levels. I also will typically adjust the exposure a little as well. The key here, for me, is to make sure I am not clipping anything nor making anything too bright while starting to bring out the color of what I am shooting. – Topaz DeNoise – the latest update brings us the Severe Noise option which feels a little better then the Low Light one. I usually put it on Auto then bring the sharpness down by half. – Astronomy Tools Actions – I try the Space Noise and Deep Space Noise options here and depending on how it effects the detail of the nebula, I may or may not go with any of them. Always good to check. I’d rather have some noise and keep structure in my nebula then loose it because the software assumed it was noise. – Astronomy Tools Actions – Enhance DSO is done here. Sometimes I like it, sometimes I don’t. If I don’t like it I just continue on to RAW filter and if I do… well, I also continue on to RAW filter! – Camera RAW Filter – minor adjustments in the basic tab. I may repeat this a couple of times – Astronomy Tools Actions – Contrast Enhancement – I run this then usually set the layers opacity to 50% or below.
At this point I flatten the image and save it as a 16bit tiff to run it through Starnet++ – an excellent program that removes stars but leaves the nebula.
While doing this, I attempt a mask using the Color Selection -> Highlights to bring out the nebulosity a bit more. A.V. Astronomy has a good video on it. Sometimes this works, sometimes it doesn’t. By this point my starless image should be done and I bring that into Photoshop, isolate the red channel, copy and paste it as a new layer in the image I am working on. From there, I set the opacity of that layer to 10% and adjust the highlights to see if I can bring out the dust a little more. Keep in mind, this will make your image a little pink versus red. This does two things – first, you can set your black point a little lower and it will offset if you clip a little bit. You can also adjust your saturation a bit more to make it more red. This layer acts as a luminance layer – though a true Ha luminance layer will work much better. What is even better, you can use both methods I mentioned in the same image! Just be careful not to over do it!
At this point I save a main image jpg, I save an inverted version and I make one more starless version to match my current process. I always make sure to keep a working Tiff file that has all my layers available in case I want to go back and try something different.
The Cygnus Loop is a large supernova remnant within the constellation Cygnus which is now visible in the night sky in the Northern Hemisphere. The entire structure is around 3 degrees in size and sits around 2,400 light years away. It has an age of around 21,000 years. This target, for me, was one of the more frustrating targets. Its unique coloring, its “whispiness” and the sheer amount of stars make it a challenging target to both shoot and more importantly, process cleanly. In total, for the Western Veil images, I got around 5 hours of data total and I feel like to get it completely “clean” I would need around 15 more total hours for a total of 20 hours on target. I am hoping to get this amount in a more wide field, which I have already begun and is shown in the images at the end of this post.
As you can see in both sets, there are a large amount of stars, even with star reduction techniques being used. The inverted images really show the star field and the deep contrast of the nebulosity.
Image & Equipment Information:
Meade Series 6000 80mm Triplet APO Refractor Canon EOS Ra Optolong L-eNhanced Filter Ho-Tech Field Flattener ZWO 30mm f4 MiniScope (guide) ZWO asi120mm (guide) Pegasus Powerbox Advanced
15 x 360s (6/16/2021) 30 x 420s (6/17/2021) Dark, flat, bias and dark flat frames for calibration ISO 800 – Taken in Providence, RI – Bortle 8
Image & Equipment Information:
Radian Raptor 61 Canon EOS Ra Optolong L-eNhanced Filter ZWO 30mm f4 MiniScope (guide) ZWO asi224mc (guide) Pegasus Powerbox Advanced
20 x 300s (6/13/2021) Dark, flat, bias and dark flat frames for calibration ISO 800 – Taken in Providence, RI – Bortle 8
Milky Way season has officially begun and that means we get to start observing and photographing beautiful nebulae. One of the most popular regions that gets looked at towards the end of Spring and the start of Summer is the constellation Cygnus. Famous constellations that include The North American Nebula, The Veil, the Crescent Nebula, and more can be found in this constellation. So far, I have been able to capture the North American and Pelican Nebulae together, which is close to the bright star Deneb, as well as the Sadr Region which includes the Crescent Nebula. Deneb and Sadr make up the two brightest stars in the Swan constellation, and around both of them is a lot of beautiful nebulae and stellar dust.
Above is the Sadr and its surrounding sky which features such Nebula like the Crescent. This area is full of rich Ha and comes out beautifully. The shot above is a total of 3 hours and 50 min integration time in one session.
Here we have the North American and Pelican Nebulae which are near the star Deneb. This is one of my favorite nebula in the night sky period. Previously, I posted these images processed as a simulated SHO. This shot is a total of 3 hours and 35 minutes integration time in one session.
I shot both of these targets with a Canon EOS Ra through the Radian Raptor 61 using and Optolong L-eNhanced filter. This is the second time I have been able to use the Raptor for what I intended it for and will be will be writing something on it soon!
I decided to go back and rework some of my data from March and see what I could come up with. After reprocessing my Rosette & Cone wide field image in a simulated SHO palette, I decided to try and do the Orion and Horsehead wide field shot.
I did the stacking, channel combining and initial processing in Astro Pixel Processor then took the image over to Photoshop. I had to do it separately for the longer exposure and then the shorter exposure to create two separate images to use to try and combine them to soften the blown out core a bit. I believe my long exposures where simply too long to be real effective, but I was able to soften it a bit. I needed the longer exposure to pull out the detail in the Horsehead and Flame Nebulae, so I will need to research a bit more if I try this again in the future. I am thinking I may need to take three different data sets at different exposures and combine them over two. For reference, I have been using AstroBackyard’s Tutorial on HDR Composites. As always, Trevor Jones provides a lot of good information!
120 x 60s 60 x 10s Darks, flats, dark flats and biases for both sets . TPO Ultrawide 180 Astrophotography Lens Canon EOS Ra Optolong L-eNhanced Filter ZWO 30mm f4 MiniScope (guide) ZWO asi 224mc (guide)
A miracle happened, I finally got some clear skies on a weekend night when the moon was not up or bright. It just so happened that Milky Way “season” has just begun so I was finally able to put my new scope – the Radian Raptor 61 – through its paces and image something I have been waiting to image since last November – The North American Nebula (NGC 7000).
Image 1 – Starless Image 2 – Negative Image 3 – Inverted Image 4 – Final Process
45 x 240s 7 x 300s (3 hours, 35 min total integration) 20 darks, 25 flats, 25 dark flats, & 50 biases 800 ISO – Bortle 8 . Radian Raptor 61 Canon EOS Ra Optolong L-eNhanced Filter Sky Watcher EQ6-R Pro ZWO 30mm f4 MiniScope (guide) ZWO ASI224MC (guide)
Imaging Notes: I felt like the focus was a little soft. I realized this about 3/4 of the way through the session and decided to roll with it and keep my fingers crossed it would end up alright. I was able to get 3 hours and 35 minutes of total integration – essentially from the moment it rose above the trees to the East until the ambient light from the pending sun rise began to wash out the nebula.
Processing Notes: Stacked and channels separated in Astro Pixel Processor – – Extracted Ha & Oiii, simulated Sii with Ha-Oiii Mono Processed in Photoshop