NGC 6888 Crescent Nebula - Ha & O3 bicolour

[badgers]

Hello everyone,

I'm sorry I've been away for so long, given the awful weather in spring and early summer, I took a break over the summer due to lack of darkness.

Anyway, the scopes are dusted off and the weather has been kind with a number of good clear nights in a row.

I decided to revisit the crescent nebula with the refractor as this target was my first real imaging success back last year with the newt.

I'm amazed at how hard it is to get OIII data on this, but if the weather holds I'll keep pushing. I guess I might need longer subs as 20 minutes seems to catch the edges of the O3 shell but not much detail.

So Far at 10 hours:

18x20 minutes O3

12x20 minutes Halpha

I've found processing the weak O3 and the incredibly strong Halpha to be really tough, but I think its beginning to shape up.

Hopefully it will be easier to manage the blue channel with more data.

I'm not sure if its worth capturing more O3 or going back to get RGB data for the stars. Maybe I'll wait until Kelling to get the RGB data as the light pollution here in the city is pretty rough.

Nice to be back and as always any comments or advice much appreciated!

Thanks for looking,

Anton

Edit: Raw O3 and Halpha below (just autostretched in PI after integration)

[Quatermass]

Very nice crescent badgers and good to see you back in action again. I took a break for a while as well but you can't stay away for long when the bug bites.

cloud cloud go away come again another day

[badgers]

Thanks Mark, it's good to be back and even better to see you are back too!

Sorry to hear about your controller problems, hope you get it fixed soon : (

Anton

[Quatermass]

I have ordered one of Tom Carpenters AstroEq units which will put an end to these duff skywatcher units and give me go to ability's and full use of eqmods many functions guiding mosaic capturing eq tour and other goodies. I love my eq5 mount. Have considered taking apart my old garden shed and turning it into an observatory ready for the winter as well.

cloud cloud go away come again another day

[JohnC64]

Hi Badgers,

Good to see you back on the forum. And a cracking return it is too. Nice outer shell on the crescent there.

John

[cloudbuster]

Really liking this..

[andyo]

A very nice crescent

[badgers]

Thanks guys, good to be back.

I'm really hitting a wall with processing these days. I'm still not happy with the image above as the OIII shell looks over-saturated and has lost detail, but it's the best result so far from trying to process these images at least 8 times.

I'll definitely get some more data when the clouds clear.

This one was processed by combining Red: Halpha Green: 80% OIII and 20% Halpha, Blue: OIII. Curves were used to bring out the shell, resulting in a reasonable but rather noisy image.

I then used the H-alpha as a luminance layer, which smooths the image beautifully but looses the OIII detail and required me to push the OIII data probably too far.

Any advice on where to go next ?

More OIII data to drop the noise ?

Should I get Luminance data and RGB data for natural colours ?

Thanks,

Anton

[Quatermass]

Dougs tutorial on using curves and avoiding noise is very helpful check out his website.

http://www.budgetastro.net/

[badgers]

I'll definitely check out his tutorials, I subscribe Dougs Flickr feed, he gets great results.

He bought my old guidecam and put it to far better use than I did!

Anton