DSLR Capture of the Heart Nebula IC 1805

As I am back to imaging on my DSLR in the short term, I wanted to test out how it would perform on a hydrogen gas nebula, now that the camera has been modded and had a filter removed. I opted for the Heart Nebula – IC 1805 – as it afforded me the most time in one session. I captured a total of 8 hours of subs, each of 240 secs at ISO 800. These were then calibrated and stacked in PixInsight, my processor of choice.

I struggled, however, to process accurately in PixInsight – one corner in particular just refused to even out and so I was faced with the prospect of some rather extreme cropping to remove stubborn gradients. That is until I tried out a trial version of Star Tools. It stripped out the gradients with ease and actually produced an image of much greater clarity and crispness than PixInsight did, despite several attempts. A quick boost in Photoshop and it was finished.

I didn’t mask the stars as well as I’d have liked and this has resulted in some ring artifacts – I know where I went wrong and may go back and have another go in the future but I’m happy overall – especially in terms of the sheer amount of nebulosity the modded Canon allowed through.

I now own a licence for Star Tools – it doesn’t replace PixInsight but, like Photoshop, it is a handy tool in my processing arsenal and can produce excellent results quite quickly. I’ll see about doing a proper review of Star Tools once I truly get to grips with it.

Stats:

Lights: 120 x 240secs (!!)

Darks: 20 (I’m going to move towards using more extreme dithering and a master bias instead of darks on the DSLR)

Flats: 50

Final image:

Stacked and calibrated in PixInsight

Processed in Star Tools

Finished in Photoshop

Heart Nebula

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Capturing The Horsehead Nebula – Barnard 33

Over the last nine months of imaging, I have learned a lot about capturing and processing images. I have also built up a list of targets I want to capture; a list primarily driven by the classic images we’ve all seen before: Andromeda, Orion Nebula and, top of my list, The Horsehead Nebula. For some reason, I had convinced myself that I wouldn’t be able to see the nebula from my backyard due to tree clearance and a neighbour’s house to my south however, I recently noticed it rising on Stellarium when planning another target’s run so I figured I’d give it a go.

I’ve had some issues recently with my QHY163m which has had to go back to China for a repair to the sensor window’s heater and so I’ve been playing around with my modded Canon 100D DSLR instead. The change back down to a DSLR has been notable, especially with the lack of narrowband opportunities. Still, I’m not going to waste any clear nights and so I’ve been re-learning the camera and settings, and imaging a few more obvious targets.

And so to imaging The Horsehead Nebula. I had a clear night last Saturday – almost 12 hours in total so I spent a while gathering more data on Andromeda and having a go at Thor’s Helmet, just to see how it turned out (better than expected but too small for anything other than an experiment). I also planned in 90 minutes on Barnard 33, just to see if I could catch a glimpse of the famous horse’s head back lit by the dramatic red of NGC 2024. I had issues with plate solving and was running out of time when I grabbed a frame that had the nebula in the corner of the frame, and at 90 degrees to where I wanted it. I decided rather than waste any more time, I’d run the sequence and hope I could crop it down.

I ran 20 frames of 240 secs each at ISO 800. These I stacked with 20 darks, and 50 flats and then processed in PixInsight. My processing was minimal as the signal was quite strong – a little noise reduction and then darkening the background with curves, and I was done. I’m really pleased to finally grab my own image of The Horsehead Nebula – it isn’t perfect but I don’t care. I know I can have more time on it as the season progresses.

Full resolution on my Astrobin page: Barnard 33 – The Horsehead Nebula

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M33 Triangulum Galaxy

Autumn has arrived and, with it, the winter galaxies are coming back into night skies. I imaged Andromeda a little earlier this autumn and also had a preliminary go at M33 a couple of weeks ago, but didn’t manage to grab any chrominance subs. I’ve also been having some issues with condensation on my camera which I am still trying to work out. This, combined with the terrible autumnal weather we’ve had, has meant I have had little time to get out and do some imaging. Last weekend, however, I had a good window of weather and so decided to have another go at M33, the Triangulum Galaxy.

M33 is approximately 3 million light years from Earth, in the constellation Triangulum, and is understood to be a satellite galaxy of Andromeda. It’s relatively small size, when compared to M31 Andromeda, and its diffuse nature, makes it harder to image from light polluted skies. This was compounded by the moon being 51% full on the night, although it was already well into western skies as M33 was rising above the treeline to the east of my imaging site.

I imaged using my QHY163m camera at -5c as I suspected that shooting at -20c was contributing to my condensation issues. I also jerry rigged a small 2″ dew heater bought I bought from a brilliant UK supplier, W&W Astro, as well as insulating the camera where the sensor window attaches to the filter wheel. This approach seemed to work as I had no dew issues all night, despite the relative humidity hitting over 90%!

I shot LRGB as follows:

120 x L – 20 secs
60 x RGB – 40 secs each

This gave a total integration time of just under 3 hours total.

The processing in Pixinsight was an arduous task, as it often is with large numbers of subs to work on, and the faint nature of the galaxy, combined with the notable sky fog when stretching, meant a compromise between drawing out the fainter wisps of outer spirals, and keeping the background sky relative flat.

I’m pleased with the overall outcome, although I want to add more data in the near future.

M33 Triangulum Galaxy Crop
M33 Triangulum Galaxy in LRGB

 

And on my Astrobin page

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