Had my first imaging night last night, this is what I got at the end of my imaging session. Just did a quick process on it, haven't gone into too much depth yet, not a lot of data to work with
10x60s RGB (30 mins total). Started imaging at 4:40 am, I am thinking that there is some strange artefacts on the right side of the image caused by the sun which was slowly starting to encroach upon the horizon (astronomical twilight).
Like many people you have chosen one of the hardest DSOs to image,
due to it's huge dynamic range.
You need some very short subs to work with to prevent the total
blowout of the trapezium which your image exhibits.
Great start though; still wondering why the image is almost monotone.
raymo
As Raymo said, if you shoot some short subs that capture the Trapezium you can then layer them in processing (which you would have to be able to do of course). This will prevent the over-exposure in the central core.
As to the color, I agree it needs more, but that could be due to my shooting the same object with a full-spectrum camera and being used to seeing it that way. Certainly your closer to monotone image is perhaps closer to a visual experience. One of the advantages of imaging is the colour potential it provides.
Great start, and you must be prepared to stay up waiting for it to rise at this time of year.
That one there was just a very quick stack in MaxIm and the. Stretched in PI. Calibration to finish in about 10 minutes
I have a feeling that there are a few bad frames in there that will have to be removed, got a bit more time this afternoon to have a play with it. The core isn't actually blown out, I did run a quick HDRTransformation on it but actually preferred the look without it :-)
You are right with the saturation though, didn't hit it too hard. Colour calibration was de-linking the stretch and letting it do it that way
It was taken with a 130mm F/5.7 refractor and a QHY9.
Did some frame culling. Down to...
6x red
7x green
7x blue
So 22 minutes total. Later this evening I am planning on doing some testing to see if having PixInsight doing all of the calibration and stacking does a better job than the 1 minute that MaxIm DL takes to do the whole thing.
P.S.
I know this one is WAY over cooked
And here is a link to Astrobin so you can see it in all its noisy goodness
I can see from the new improved version that there is plenty of data
there to produce a nice image. I know nothing about any of the software
you are using, so can't help there. I don't know what's going on with
the colours, they are strange, and muted. Did you produce these colours, or did you leave the software to it's own devices colourwise. M42 is full
of red and blue, and some brown.
raymo
I can see from the new improved version that there is plenty of data
there to produce a nice image. I know nothing about any of the software
you are using, so can't help there. I don't know what's going on with
the colours, they are strange, and muted. Did you produce these colours, or did you leave the software to it's own devices colourwise. M42 is full
of red and blue, and some brown.
raymo
I've just left the software to its own devices. Not always the best idea I'll admit but I do agree with you on the colours. The auto white balance that my D700 got was really good and it never showed anything but red and blue, no golden green.
That explains the colours. If your software is anything like all other
stacking software that I've come across, it produces a washed out
almost monotone image. You have to process the image yourself
to end up with the desired colour, contrast, and saturation.
raymo
What made it difficult with my last version was that each exposure wasn't long enough to get half decent colour signal.
Made another attempt at capturing data. Started off really well, got the first three frames and then my QHY9 glitched while I was napping. I think I am going to have to remove the filter wheel from connecting to the USBHub.
Got 1x200s RGB so 10 mins total.
Flats, Darks and Bias applied. Difficult to control noise with one frame each.
This was mostly just a test of the telescope without the Flattener Reducer.
Much nicer Colin, but now a mechanical issue I spotted - look at the star I have circled. That is an intrusion into the light path by something like a lens spacer foil, screw head, or even a bug! Have a look down the front and see what may be causing that diffraction artifact. Most commonly it is foil spacers, which can be corrected by disassembly and moving/trimming (Andy's shot glass page tells how to do this) or making a VERY slight aperture mask to cut off that area just enough.
Or have Cris have a look at it. He should be able to help.
With more exposure and stacking, it will compound. And brighter stars will show it even more.
(there are more in the image, just pointed out a few)
I did image this through a William Optics Dielectric Diagonal, only way to achieve focus without. It probably has a few bits of grit and stuff on the mirror, could this cause it OR does it have to be in the front end of the optics to cause this?
Get yourself some 2" extensions (Andrews had them cheap - GSO) and find out. Start eliminating possibilities.
I DOUBT a diagonal - more likely something further up the tube - maybe even an errant baffle.
It is SMALL, but like I said, will magnify it's impact with longer subs etc. If you aren't far from Cris, might be worth a drive over to Bentleigh for him to take a look. It should be easily correctable.
Start by looking at the foil spacers - more often than not, one or more will intrude into the light path enough. Vixen for example are notorious for this - my FL102S made PERFECT 6 point diffraction spikes caused by the foil spacers! Easily corrected with an appropriately sized aperture mask (my mask was 100mm - reduced the effective diameter 2mm)
If not the spacers, look for any roughness to the edges of the baffles, or even a spider web or similar.
It was just a spur of the moment decision hehe Didn't think I was going to need more back focus and I had a diagonal next to me at the time. Only wanted to see how the telescope performed photographically without the flattener/reducer.
I'll have a look at the lens' this evening between getting home from work and heading to the airport to fly to Darwin :-)
