My Summer Holiday Processing Marathon

[Whistlin Bob]

Just had a lovely couple of weeks away with the family in France. A combination of cloud and light pollution meant I didn't get the chance to do any actual astronomy whilst I was away, but I did stack up a pile of data in the manic few weeks before I went away (I seem to need to work twice as hard before I go on holiday!!!), with a series of clear nights in the first week of August allowing a sequence of overnight sessions. 

Dataset 1 of 5:  This is a wide shot of the Crescent Nebula area using a Skywatcher 72ed with an ASI1600 camera and Baader UNB filters. I captured the Ha for this back at the start of July, but didn't get a chance to go after the Oiii until August. The exposure time for this is 2 hours of Ha in 3 min subs and 3 hours of Oiii, plus 30 mins of RGB for the stars, stacked in DSS and then processed in Pixinsight. Approach was to register all of the stacks against each other, then strip the stars out of the 2 narrowband channels with StarXTerminator. The Ha stack, as always, is much stronger so it dominates the final image being all of the red channel, and with the strongest bits fed through into Blue and Green as well to bring out some of the texture of the nebula. 

I then added in the stars from the RGB dataset. I think in  this dataset I prefer the starless version because it really exposes the structure of the nebula.

[Whistlin Bob]

Dataset 2 of 5: M27. This is the only dataset not from the 72ed/asi1600 combo and was the first successful test of a a second rig I've been putting together- this is a 130pds, with one of the new SvBony 405c cameras and an Altair 4nm filter. This is 22 3 minute subs, plus 15 minutes with an IDAS light pollution filter to get some colour in the stars. Quite pleased to get the "wings" on the sides of this one with only just over an hour of integration.

Edited August 29, 2022 by Whistlin Bob
Typo

[Whistlin Bob]

Dataset 3 of 5: Elephant's Trunk. Really pleased with this one. Like the Crescent, I got the Ha for this over 2 hours back in June (very limited darkness!), plus my standard 30 mins of RGB. The Oiii and Sii are both 3 hours from the 72ed rig. I got plenty from all channels so was able to do an SHO on this, although looking at it now it's a touch noisy. Might have a go with Topaz on this. Presented with starry and starless versions.

 

[Whistlin Bob]

Dataset 4 of 5: The Cave Nebula. Oh man this one was a pain. I've got 4 hours of Ha here, plus I also gathered 3 hours each of Sii and Oiii, but on processing them I just couldn't get a result that to me looked attractive- the channels were just too weak, except around the mouth of the cave itself. In the end I just went for HaRGB, and it's still a a little soft from the noise reduction. I have to say that I admire the dedication of imagers who are willing to dedicate so many of the meagre hours that we get in the UK to gathering data to perfect a single image- it can be such a massive test of your patience.
 

[Whistlin Bob]

Dataset 5 of 5: North America Nebula. After fighting with the Cave data it was great to have a play wth a much stronger dataset. This is 2 hours per channel plus 30 mins RGB. The first image is just the RGB with no other filters taken in Bortle 5- I'm amazed at how much nebula has come through. 

Then we have SHO. Again- in this instance I really like the faint detail on the starless version that's visible to the north of the nebula that's otherwise lost in the stars. I've also tried quite hard to bring out the different structures and textures within the nebula. I think this leads to it looking a bit more "messy" but I prefer the the greater detail, and after the frustrations with the Cave it's nice to work with a dataset that gives so much. 

As usual, I started obsessing over small details-this time it was trying to get the stars back in so that they didn't appear "stuck on", especially compared with the lovely stars in the RGB image. I've added a bit of "haze" around the before adding back in- I still haven't quite got the colours, but it looks better than it did.

Thanks for looking!

 

[MartinB]

Crikey you have been busy Bob.  Some cracking images there.  You must be worn out!