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Re: M42 chronicles

Posted: Sun Jan 06, 2019 9:40 pm
by turfpit
Don

Sorry for the delayed response, I have just spent 2 days on my daughters roof - much easier than capturing photons ;)

I have created a comprehensive post about my latest M42 capture in the Gallery viewtopic.php?f=16&t=1347. This should answer your questions. Yes the captures were 90 seconds per frame, 30 of them being stacked along with dark, bias and flat frames.

The equipment I am using now I consider modest but serves me well when attention is paid to detail. The camera is an Atik 314E CCD (released circa 2010) second hand obtained off eBay at a cost £300 (would have been ~£1200 new); the mount is a Celestron AVX Equatorial Mount, second hand from AstroBuySell at a cost of £500, the telescope an Altair 66ED-R refractor, an ex-demo model at a cost of £260; Bahtinov Mask cost around £15. This scope does not have a motorised focuser - I manage quite well with the 10:1 manual focuser. The JMI motorised focuser is on my Celestron C8. Note that the mount cost was roughly the same as scope + camera cost.

I have made some poor equipment choices in the past and accept that progress in this hobby is evolutionary rather than revolutionary.

I think if I had the above gear when I started out I would still have bloated stars, star trails and poor tracking - progress in this hobby is hard won and requires discipline and persistence. Spending ££££££'s does not equate to success.

I now have a 200mm F4 lens, which I can use instead of a telescope. This year my focus will be on trying to achieve shots
like this http://www.clarkvision.com/galleries/ga ... b5x5s.html

Also this year I will strive to improve my capture/processing to try to produce images like https://www.dpreview.com/forums/post/62123971.

I still the have equipment used to create the image at the top of this thread. I think I will give it a run with the cctv video camera next partly cloudy night. I will use Live Stack - that should be interesting as I haven't used Live Stack or that camera since I created the examples for the Sharpcap 2.9 manual. I will capture M42 again and post to the Gallery, weather permitting.

I think astro-imaging is a fantastic hobby - there are no targets, deadlines or limitations. Anyone can do, or spend, as much or as little as they please.

Take note of the comments in this thread from Rob. I, for one, am in complete agreement with his statements.

Good luck with your imaging .

Dave

Re: M42 chronicles

Posted: Fri Mar 08, 2019 6:48 am
by turfpit
Taken 27 Feb 2019 from a village hall car park using an Altair 183M.

Dave

__M42-60x60s-g200-bl30.jpg
__M42-60x60s-g200-bl30.jpg (112.2 KiB) Viewed 424 times

Re: M42 chronicles

Posted: Sun Aug 11, 2019 1:24 am
by turfpit
This is a re-processed stack of my image posted Oct 22 in this thread. Same stack but more processing carried out in Siril - specifically Background Extraction. I am badly affected by the light pollution from the Manchester conurbation. The Background Extraction process removes the bad light gradient across an image.
https://www.astrobin.com/370493/E/


_M42-100x15s-183C.jpg
_M42-100x15s-183C.jpg (244.53 KiB) Viewed 274 times

In Siril
  • Crop
  • Background extraction (Generate, Apply)
  • Colour calibration
  • Colour saturation
  • Green noise removal
  • Histogram transformation

In GIMP
  • Apply ‘S’ shaped curve
  • Contrast

The bright pink is the Manchester side of the image.
before-background-extraction.jpg
before-background-extraction.jpg (152.39 KiB) Viewed 274 times

background-extraction-in-Siril.jpg
background-extraction-in-Siril.jpg (25.19 KiB) Viewed 274 times

background-extraction-in-progress.jpg
background-extraction-in-progress.jpg (120.28 KiB) Viewed 274 times

after-background-extraction.jpg
after-background-extraction.jpg (151.4 KiB) Viewed 274 times


This is the RGB histogram in GIMP. The colour balance came out reasonably ok considering I had to make no adjustments.
RGB-histogram.JPG
RGB-histogram.JPG (45.01 KiB) Viewed 265 times


I would hope to improve on that this year as I am now using more calibration frames.

Dave

Re: M42 chronicles

Posted: Mon Aug 12, 2019 10:00 am
by turfpit
I cropped to leave only M42/M43, with slight adjustment to Colors > Curves in GIMP. Use of Background Extraction has certainly helped to preserve detail and colour.

M42-M43-crop.jpg
M42-M43-crop.jpg (219.41 KiB) Viewed 256 times
Dave

Re: M42 chronicles

Posted: Tue Aug 13, 2019 1:03 pm
by mAnKiNd
Super thread! keep it up :)

Re: M42 chronicles

Posted: Tue Aug 13, 2019 10:26 pm
by turfpit
Cheers Minos.