Here's a raw stack of the Soul Nebula (IC 1848) taken over 2 nights at Kelling Heath. In total this is 10 hours of data in 5 minute subs at ISO 800 i.e. 120 subs!
The usual modded Canon 350D on the Tak Epsilon 180 ED.
(http://www.markshelley.co.uk/Astronomy/2012/soul14092012small.jpg)
You'll notice hot pixels because the sigma stacking didn't work across both night's data - probably because the sky gradients were very different on both nights. So I'll have to process both nights separately and then combine. I also need to shoot some shorter subs so I can control the brighter stars a bit better.
However, this quick stack gives a good idea of what the final image will be like.
Here's a larger version:
http://www.markshelley.co.uk/Astronomy/2012/soul14092012.jpg
Mark
Looking very nice Mark- superb colours as usual... Impressed that you spend so long on a single target... john
Quote from: JohnP
Impressed that you spend so long on a single target
Spending so long on a single target is necessary to overcome the limitations of the DSLR - in my opinion anyway. Having said that, a long total exposure will make a big difference whatever camera you use.
Mark
Looking good Mark, can't wait to see the final version.
Robert
That's looking very nice and I agree with Robert - can't wait for the final.
Are you processing in Iris or Pixinsight ?
Very nice.
Mac.
It's going to be another corker Mark. Processed in IRIS?
Quote from: mickw
Are you processing in Iris or Pixinsight ?
Quote from: The Thing
Processed in IRIS?
Initial stack (or stacks) I do in IRIS because it's much quicker than PixInsight and because my humble XP machine runs out of memory doing huge stacks in PixInsight. Subsequent processing is (or will be) a mixture of IRIS and PixInsight.
Will be fantastic, as always from you, Mark!
Mark, just out of curiosity why do you use Iris to stack and not something like Deep Sky Stacker? Is there any advantage or is it just personal preference?
Considering how much time you have spent imaging this and your excellent skills Mark, this must be one hell of a faint object.
Looking forward to the final result.
Carole
Tonight's forecast is for a clear night with excellent transparency and no dew. I hope to get a 3rd night of data after shooting some short subs to better control the brighter stars.
Quote from: Carole
Considering how much time you have spent imaging this and your excellent skills Mark, this must be one hell of a faint object.
It's faint but not too faint. I haven't processed it to its full extent yet.
Quote from: Mike
Mark, just out of curiosity why do you use Iris to stack and not something like Deep Sky Stacker? Is there any advantage or is it just personal preference?
I use IRIS because I love its speed and flexibility. Also, I've had one or two duff results with DSS for reasons unknown.
With IRIS I can save intermediate stages of the processing e.g. save the calibrated subs, the aligned subs etc.
I can then go back and do a re-process from an earlier stage. e.g. if I discover a dodgy sub affecting the final stack I can remove it and simply re-sum the already aligned frames.
I wrote an IRIS script (I believe Duncan also uses it) which makes it almost as easy to use as DSS - I set it off and go to bed.
The only weakness I'm currently hitting is that it only uses a 16bit integer representation, so it can't create or save HDR (high dynamic range) files.
I'm gradually migrating to PixInsight because it is even more flexible and even more powerful. But it is slower than IRIS and is a memory hogger - it crashes on XP with a memory exception when I process more than 100 subs. But I can't complain because the documentation specifically says not to use it with XP.
Mark
Any nce of posting up that Iris script again Mark, perhaps on the stickys, I can't remember what I did with it, might have another go at it.
Carole
Quote from: Carole
Any nce of posting up that Iris script again Mark, perhaps on the stickys, I can't remember what I did with it, might have another go at it.
Here:
http://forum.orpington-astronomy.org.uk/index.php?topic=8232
There was one you wrote more specifically for the layman Mark, the one on that link looks very technical and mathmatical.
Carole
Carole wants your crib sheet (http://www.markshelley.co.uk/webdisk/IRIS_Cribsheet.doc).
Grabbed another 5 hours last night. SQM at High Halden was only 20.9 instead of Kelling's 21.3 or 21.38 :-(
However, looking at the subs, the difference is actually fairly marginal in terms of background noise levels.
Just when I thought I had finished the processing, I find some hot pixels. So I need to do another full re-process. Buit apart from the hot pixels, I'm pretty happy with this.
180 x 5min at ISO 800 (15 hours in total over 3 nights - 2 at Kelling, 1 at home).
Modified Canon 350D on Tak Epsilon 180ED at F2.8
No filters except the IR/UV rejection filter.
(http://www.markshelley.co.uk/Astronomy/2012/soul14092012v2_small.jpg)
Larger version here:
http://www.markshelley.co.uk/Astronomy/2012/soul14092012v2.jpg
Mark
Very nice Mark, love the star colours, what a marathon!!!
superb Mark (as usual) - still waiting for the book announcement... John
Absolutely gorgeous Mark.
I love your star colours, I can never seem to get decent star colours, and I wonder whether it is because I use DSS and you use Iris.
Carole
Lovely image Mark. Definitely a calendar contender!!
It is obvious from my own experiences with the DSLR, particularly on a smaller aperture than you have, that what you say about getting as many hours as possible exposure certainly applies. They may be easier in some respects than a cooled CCD camera to use but at the same time you need significantly greater exposure times to get the same results. Oh how I miss my SXV-H9.