M42

[oska]

Just for fun with heavy dew.

275 x 15s (68mins)
-10c 139g Calibrated.
ASI1600MC EON85

[xelasnave]

A wonderful image and you can be proud ..even here I can see the trap stars..so often folk blow out this region entirely..
Very well done.
Alex

[AstroViking]

Fantastic image, John.

I can see a lot of subtle detail in colour in the gas/dust clouds, and as Alex said, the central core and the stars are not blown out.

Cheers,
V

[oska]

Thanks Alex & Steve I am pretty happy with it. It was a weird night. It feels like a fluke :)

[Doogs38]

Wow! That’s a superb image in all regards, John. If I could get an image of M42 that looked half as good as yours, I’d be smiling for weeks. Was it taken from the burbs or did you get out of town? Also, did you take short exposures as an experiment (noting how bright M42 is) or because of prior experience? Regardless, your resultant image has a very wide dynamic range which has preserved a superb amount of detail from the core and out … kinda like a HDR image. Noice! Alex

[oska]

Thanks Alex, I was jus f'n around ;) I'm in bortle 4, I think. I was totally surprised, a fluke even :)
I used the optimal exposure calculator (plugin?) in nina. I think it uses the exposure calculation method championed by Joh Rista which targets swamping read noise using your current camera, filter, target and seeing taken into account, at least afaik.

I did the usual Dynamic Background Extraction (divide & subtract), Photometric Colour Cal. and ezDenoise. The sneaky part came to the stretch. I did a small histogram stretch incrementally until the core showed with good definition of the brightest stars but nowhere near swamped. I then applied a range mask that covered the bright bits and then continued with the small stretch increments until you could just notice the mask, hit undo once or twice and then redid the range mask to cover the brightest bits and incrementally stretched again. Three range mask steps, heaps of little histogram nudges.
Then it was a little contrast curve and a little touch of saturation. done.


Ok this time I'll admit I had a big smile on my face. I actually got roughly what I meant to. I started from scratch, granted with an excellent kit, in May.

Here are the (inverted) masks I used:

[Dave882]

That’s a beautiful result! Beautiful detail and yes great control of the trap. Looks like you’re really getting the hang of PI- something I’m not yet game to attempt :lol:

[oska]

Cheers Dave, kinda slowly. I've tried others but one headache at a time ;)

[Doogs38]

Thanks John, for the info on your PI technique :thumbsup: I have a trial version of PI and will try this on my Tarantula data, it too is very easy to blow highlights being such a bright nebula. Looking forward to seeing more of your images … you must get more clear nights then us cloud-bound southerners <insert sympathy here :lol:>!

[oska]

No worries Alex, cheers. I only got this far (up mount stupid, I might be able to see the top from here or maybe it's just a rock) from listening to others.

We seem, well I do, quite lucky in that regard. I get more grief from the moon than the clouds, sometimes both at once - like tonight. I wont sulk... in public.