Lagoon Nebula | A/Prof. Ángel R. López-Sánchez

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Image

The Lagoon Nebula from Sydney

Updated version of my test image of the Lagoon Nebula (M8) with the first light of the ZWO ASI1600MM Pro camera and broad-band filters.

This image combines:

39 x 120s H-alpha (Baader 3.5nm ultra-narrow filter), in red. Darks and flats included.
40 x 15s OPTOLONG L-Pro filter, in green. No flat or darks.
28 x 300s [O III] 3 nm ultra-narrow Antlia filter, in green. Includes darks and flat (this image is the new addition).
56 x 6s ZWO B filter, in blue, no flat or dark.

H-alpha data taken on 21st Aug 2020, L-Pro and B data taken on 23rd Aug 2020, from my backyard at home, 15 km North from Sydney’s city center.

Telescope: Skywatcher Black Diamond 80, f=600mm (f/7.5)

Equipment: I used the ZWO ASIAir to control the camera, the mount (Skywatcher AZ-EQ6) and the guiding system (ASI120MM + Orion 50mm finderscope). ZWO filter drawer for changing filter.

The [O III] data taken on 18 August 2021, including the Orion 0.75x focal reducer and the ZWO 7×2″ filter wheel.

Processing: Data processed with Siril software. FITS converted on TIFF using NASA’s Fits Liberator considering a logarithmic function. Color / saturation / levels / contrast / smart sharpen with Photoshop.

Full resolution image in my Flickr.

Credit: Ángel R. López-Sánchez (AAO-MQ).

Test of M8 from Sydney

Test image of M 8 (The Lagoon Nebula) from my backyard, 15 km North from Sydney’s city center, on 21st Aug 2019.

That was my first attempt to get the new equipment working. I was testing the Skywatcher AZ-EQ6 mount and the ZWO ASI120MM (guiding) and ZWO ASI178MC (main camera) with the ASIair. But I had plenty of problems to get the guiding working as the mount was not properly aligned to the South Celestial Pole (over Sydney, very difficult to see the faint stars using the polar scope of the mount). I had to use the drift method. After that, getting the ASIair properly guiding was hard as I couldn’t find any easy manual and never used PHD for guiding before.

This image combines 25 (of a series of 60) good 180s frames using the ZWO 183MC and my Skywatcher Black Diamond 80 (F=600mm, f/7.5. No darks, flats, biases or light pollution filter was used for this.

Later it was also tricky for me to play with the raw data: I have never used a color camera producing .FITS files before! It took me some time to get a good free(*) software for it and I found Siril. But the “bayer” decomposition didn’t work well with the ZWO cameras and my images had very weird colours.

In March 2020 I learnt a couple of extra things, including changing the bayer matrix from RGGB to GBRG for ZWO cameras and… bingo! So here it is the test image I got that night more than half a year ago! And still testing the equipment!

Ah, yes, stretching, colour contrast, saturation, levels, and luminosity with Photoshop.

Full resolution image in my Flickr.

Credit: Ángel R. López-Sánchez (AAO-MQ).

(*) Don’t get me wrong… I’ll get PixInsight eventually, when I get everything working well.