M42 Orion Nebula

[Carole]

I haven't imaged this target for many years, mainly due to it only being up during the winter and me being at my LP home, but also because next door's tree has grown somewhat and in recent years completely obscures Orion for 3 hours per night, so I get one hour before it disappears and maybe 2 hours after it emerges. 

I was moaning about this to Dave, one of the non members who goes to Cairds (of the use a tin of Baked Beans as a counter-weight fame).  So Dave suggested I went to his house in Swanley where he gets a clear run at Orion, and where his skies are Bortle 6, rather than my Bortle 8.   

So that's what I did over this last long weekend.  I went Friday and managed to image 4 nights on the trot, though there were some cloudy patches here and there.  I came home during the day time, to eat and get things done at home as well as walk the dog and keep Adrian company, especially as Monday was his Birthday.

I used my Hutech Idas LPS P2 LP filter (that Roberto recommended) in place of the Luminance filter.
I could not find the on-line tutorial I used to use for compositing the long and short images, so ended up doing selective layering and stretching in several iterations, in each of the filters which was very tedious.  I have since contacted the author Jerry Lodriguss who has pointed me to it's new location, so at least i have it for the future. 

Hutech Idas LP filter as Luminance 11 x 600
Ha 7nm 11 x 600
RGB 24 x 150secs binned x 2
All with individual shorter subs for the core
Total imaging time 6 hours

Atik460EX
WOZS71
HEQ5

Link to Astrobin for those who can't see the image:
https://www.astrobin.com/full/6bo454/D/

[MarkS]

That's a great image of a favourite target.  You have plenty of dust showing there!

The colour goes a bit strange (purple) near the Trapezium.  I'm not sure why that should be.

Mark

[Carole]

Thanks Mark, nice to see you back. 

I think the funny colour was as a result of my manual combining of the core.  I had to do selective layering and stretching in all the channels, it was quote a chore.

Now I have managed to get hold of the original tutorial which uses masks, I am going to give it another "go". 

Carole

[RobertM]

Very nice that Carole.  Any idea what's causing the haloes around the brighter stars ?

Robert

[Carole]

Thanks Robert. 

It bothers me as well.  I think part of it is my desire to increase the star colour, but also the blue always seems to have larger stars and halos (and yes I did refocus), which I shrunk in processing, but it did not shrink the halos.  I can only assume it is the blue filter causing it.   I have had another "go" at shrinking them".

Is this better?



Carole

[Roberto]

Excellent image Carole!  The dust shows all over the nebula, confirming that the LP filter lets the "right light" in!  You can colour calibrate it using different software. PixInsight has a routine which allows for colour extinction due to altitude.  I know you don't use PxI but perhaps try other tools such as Startool's (https://www.startools.org/modules/color) or  Photoshop (bottom of this link http://www.astropix.com/html/i_astrop/customwb.html) or eXcalibrator?  http://bf-astro.com/eXcalibrator/excalibrator.htm

Roberto

[Carole]

Hi Roberto, yes I think the Hutech Idas filter worked well.

I'll have a chat with you some time about colour calibration as as far as I know I do all the right things for this in my work flow, but just maybe there is something missing.  I have had some good teachers, so I hope there is nothing missing.

Carole

[Carole]

Had another go at the Core.

[ApophisAstros]

Looking good , i always think the centre looks like a parrots beak..
Roger

[Carole]

Yes it does never thought of that before.

Carole