M42 and the Rosette

[Paulyman (Paul)]

Last night was clear which I wasn't expecting. So I took the rig out again to continue working on getting guiding working. Had little joy on that front but it passed the time until M42 rose out of the murk.

I managed 3 hours of 60s subs at iso 800, which brings my total integration time to 5 hours. I am really happy to see the faint brown dust starting to make its presence felt, particularly around the Running Man. Processing is becoming easier the more data I obtain as well which is nice.

I then decided to have another go at guiding and tried something I hadn't done before. I lowered the gain of the 290 Mini in PHD2 and almost instantly I was getting much better SNR with 3s exposures and my RA RMS dropped to 1.5" and the DEC stayed happy around 0.9". It was by no means perfect, still quite spikey and had big jumps out towards 3" but the proof that I am at least on the way is below. Two 10 minute exposures at iso 100 to see just what would happen. The only reason I only managed 2 was that I had a cable snag and it was nearly dawn.

[ChrisV (Chris)]

Very nice M42 Paul. Nice color and detail there. Given you have 4 hours you could possibly pull a lot more out in processing. How are you doing this?

[xelasnave]

Hi Paul
Sorry I only now noticed your post.
Nice work you should be very happy with your result.
As Chris said there is probably a lot more hidden in your image.
Alex

[sil (Steve)]

nice shots, your Rosette shows a bunch of hot pixels, that target will really need darks/bias/flats and a ton of lights to give you good signal to pull it forward. Orion is obviously one of the first targets everyone does. Yours is looking great . More subs will let you bring out more of the wider structure and the core is a challenge in processing too. Working with a mask to stretch the core less will help you here.

[Paulyman (Paul)]

Thanks Chris and Alex. I can definitely get more faint detail out, but my skills at present can't do that while also keeping the large amount of noise from the 550D in spring under control. So I stayed conservative. I'm currently using Photoshop but beginning the long journey of learning Pixinsight.

Thanks also Sil. The Rosette was purely a proof of concept to myself that I had at least got guiding working, so no calibration frames at all. When the crazy winds finally subside I can try guiding again and will be trying to get a few hours on the Rosette. I'm hoping longer exposures will boost my SNR enough to help mitigate the noise issues above a little bit.

[ChrisV (Chris)]

Should get some nice shots with that camera. I had one that I astro modded by pulling out the IR filter. It gave some nice shots.

[Paulyman (Paul)]

Here's another attempt at processing this time with PixInsight. There is definitely a lot hidden in the background but it comes at the expense of noise, which I haven't learned to properly reduce yet.

[sil (Steve)]

Originally Posted by Paulyman

There is definitely a lot hidden in the background but it comes at the expense of noise, which I haven't learned to properly reduce yet.

More subs, thats exactly the point of lots of subs: gathering as much of that "hidden" signal even if you cant see it in a sub, its there buried deep. Stacking then strengthens that signal and suppresses the noise allowing you to stretch the signal further before the noise comes to the front again.

You should also look into using masks, eg using the lightness channel from your integration as a mask to allow you to stretch the faint structure forward. Run noise reduction or even a blur on the mask and subtract a star mask and region mask to protect stars and nebula core. But more subs even from different nights, will immediately help you out with your current processing workflow.