SharpCap Forums

M82 Cigar Galaxy in multiband (broadband, narrowband and infrared)

Shot over 7 nights including moon, clouds, and so on. Total integration time of 12:50 hours. First time of mixing this divers amount of data and was fun to do.
Made a color version and also a slightly enlarged negative version. I always find that in negative things are getting noticed differently.
I hoped on more detail but realized that I only have an 8" scope, don't use guiding and am in the middle of a city with Bortle 7/8.
So I'm content with the result

The 3000px color version can be seen here: https://i.ibb.co/5Mbp9Td/M82-Multiband.jpg

Bortle 7/8
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC mount (no guiding)
Optolong L-eNhance filter
Baader Neodymium Skyglow filter
Baader IR-Pass 685nm filter
Zwo ASI071MC Pro camera

Captured with SharpCap Pro @ -10 Celsius / White balance R50 B50
Baader Neodymium filter
14 x 222 sec / Gain 0 / Offset 4
42 x 120 sec / Gain 120 / Offset 10
Baader IR-Pass filter
10 x 600 sec / Gain 90 / Offset 4
Optolong L-eNhance filter
54 x 600 sec / Gain 90/ Offset 4

Stacked with DeepSkyStacker
Narrowband and IR stacked together, broadband apart

Processed with Siril and Photoshop
Siril: Background Extraction and Histogram
Photoshop: layered the 2 stacked images. Multiple steps o.a. Curves, Levels, Camera Raw Filter (blacks, saturation, clarity, noise reduction), a bit of dimension reduction

Thirteen hours! That is true dedication, Menno.

Brian

Very good Menno. Have a cigar!

Dave

oopfan wrote: ↑Mon May 10, 2021 10:22 pm Thirteen hours! That is true dedication, Menno.

Brian

Thanks Brian! And yes, I more and more am starting to enjoy the act of gathering data

turfpit wrote: ↑Tue May 11, 2021 6:29 am Very good Menno. Have a cigar!

Dave

Thanks Dave! I will, together with some whiskey

Menno

Worth posting that on Astrobin. I think up to 10 images is free.

Dave

Your filter worked great to bring out the HII Menno and I agree with you about the value of the negative contrast images - one sees completely different detail in them.
TimH

turfpit wrote: ↑Tue May 11, 2021 9:02 am Menno

Worth posting that on Astrobin. I think up to 10 images is free.

Dave

Been thinking about that Dave. But also thinking on a total re-design of my own site. Till now that's dedicated to my art but thinking about doing a total format and then an art part and an astro part.

timh wrote: ↑Tue May 11, 2021 8:59 pm Your filter worked great to bring out the HII Menno and I agree with you about the value of the negative contrast images - one sees completely different detail in them.
TimH

Thanks Tim! And yes, the filter works great. I used it on 23 + 24 April with almost a full moon and it captured all just fine

Menno

Okay, this is the final re-processing of captures with Ha data in it.
Here again I now did stack and process the Ha and RGB data separately and then used the merged RGB and Ha red channel data in the red channel of the RGB.
Also, for me new, I discovered that if I lower the contrast a little bit as one of the first steps of processing, the fainter parts also are better visible.
It sounds counterintuitive but it really enhances it all. The contrast will come back with other processing like stretching and color enhancement.
To make it clearer visible, here a double take: on the left the original processing with Ha added and merged through overlays in Photoshop.
On the right with the way described above.

Menno

Hi Menno,

Very nice. Always makes me smile when I read the word "final" in the context of image processing

Tim

Ehr, yeah ... that is indeed "final" Tim
But I had a few past sessions in mind for re-processing with Ha in the RGB red-channel and that's done now.
But I'm 100% sure I'll experiment again with those sessions when I find something new with processing

Menno