M8 (Lagoon) and M20 (Trifid) Nebulae in wide field

[Amaranthus (Barry)]

A famous region towards the heart of the galaxy, captured in wide field (about 3.5 x 2.3 degrees). The Lagoon Nebula (M8 or NGC 6523) is a vast cloud of interstellar gas in the constellation Sagittarius (55 x 20 light years across). To the lower right is the Trifid Nebula (M20 or NGC 6541), another colourful HII region. They are located 4,100 to 5,200 light years from Earth.

Taken on 2 August using an ED80T CF astrograph refractor with Sony NEX-3 OSC DSLR @ ISO800 (unmodified).

The image was captured in urban (Bortle 6 skies), and is composed of a layered blend of 25 x 5 min and 50 x 30 sec subs (culled from a larger batch). Total integration = 2.5 hours

Guided using Metaguide with an ASI120MM-S camera.

Captured and pre-processed with flats (light box), bad pixel map and bias in Nebulosity. Post-processed in StarTools.

Full capture/processing details and high rez version here: http://www.astrobin.com/114602/

I'd encourage you to look at the more detailed version on Astrobin!
http://cdn.astrobin.com/images/thumb..._watermark.jpg

[Amaranthus (Barry)]

I plan to follow up with some tighter shots with narrow-band filters using a SSG3, when the skies next allow!

[Camelopardalis (Dunk)]

Beautifully detailed with lovely colours in there, well done Barry

[PeterEde (Peter)]

Very nice Barry

[Amaranthus (Barry)]

Thanks folks - I was pretty happy with it.

The idea of the two durations was to emphasize the nebulosity of M8 & M20, and the deep yellow colour of the background starfields using the long (5 min) subs, and then use the short (30 sec) subs to cut back the glare of the bright stars and keeping a nice round shape to them.

But in post-processing, I found that I could probably have done just as well with more data from just the longs, and the rest of the work via masking. It seems a rare time that more than 1 exposure length is actually really needed (M42 core and...?)

[cometcatcher (Kevin)]

Beautiful image Barry.

Other than M42, some globulars with bright cores like 47 Tuc need short core subs.