Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: The Thing on Jun 29, 2017, 13:57:46

Title: M8 Lagoon Nebula, May 2017 France
Post by: The Thing on Jun 29, 2017, 13:57:46
Hi All,

I've always wanted to image this as it was one of the first nebulae I looked at when I first took a telescope to France. I've been learning PixInsight and hope I've made a passable attempt at processing this image made using my new scope. It's made of 51x300s @iso1600 with 20 flats, 20 darks and 15 bias/offset images for calibration. It's been a real pain to get a version that looks right in a web browser, I've had to turn down the brightness and contrast significantly even though it looked fine on my main monitor. As usual click for a larger version.


Image date, time and location:           2017-05-22 02:00 France
Telescope aperture and focal ratio:   Telescope Service TS1506 Carbon Newtonian 150mm f4
Camera and filters used:                   Canon 1100d Modded, Baader MPCC
Processing applied:                           Pixinsight, Irfanview

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/normal_M8_Lagoon_PX_v2_prtscr_IV_2_.jpg) (http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/M8_Lagoon_PX_v2_prtscr_IV_2_.jpg)
Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: Carole on Jun 29, 2017, 14:28:26
It looks like you have collected some good data there Duncan, this is a very busy area with stars as it's right in the heart of the galaxy, so many in fact it makes the nebula look like it has measles.  Only thing I don't like is the green cast over the background.

The zoomed in version actually looks much nicer than the non zoomed in version.  Can't work out why that is.  It almost looks slightly out of focus on the smaller version, yet when you click on it it looks perfectly fine on the larger version. 

I know nothing about Pixinsight so can't advise there.

Carole
Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: Fay on Jun 30, 2017, 07:42:50
It would be interesting to see how it looks when processed in your normal way...it looked great in France
Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: The Thing on Jun 30, 2017, 10:07:52
Quote from: Carole on Jun 29, 2017, 14:28:26
It looks like you have collected some good data there Duncan, this is a very busy area with stars as it's right in the heart of the galaxy, so many in fact it makes the nebula look like it has measles.  Only thing I don't like is the green cast over the background.

The zoomed in version actually looks much nicer than the non zoomed in version.  Can't work out why that is.  It almost looks slightly out of focus on the smaller version, yet when you click on it it looks perfectly fine on the larger version. 

I know nothing about Pixinsight so can't advise there.

Carole
Hi Carole,

Don't know where the green came from, I desaturated the green to try and avoid just this! Looks very slight in the forum version on both my monitors. The small version is created by the Gallery software so the softness must have come from there. The uploaded original is a 95% quality JPG.
Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: Carole on Jun 30, 2017, 12:48:29
QuoteLooks very slight in the forum version on both my monitors.

Strange how it appears on different monitors as it looks quite strong on mine.

Carole

Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: The Thing on Jun 30, 2017, 14:47:51
Quote from: Carole on Jun 30, 2017, 12:48:29
QuoteLooks very slight in the forum version on both my monitors.

Strange how it appears on different monitors as it looks quite strong on mine.

Carole

Indeed, I am going to see if I can re-calibrate my monitors before I try any more post-processing, green is not a good tint in 99% of astro images! I used to have a hardware calibration gadget which was excellent and simple to use but it ceased about two windows versions ago. Time to go shopping.
Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: Carole on Jun 30, 2017, 15:50:56
It doesn't look so bad on my phone, perhaps its my monitor.  Going to try it on  my laptops and see what it looks like on them.
Carole
Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: JohnP on Jun 30, 2017, 19:29:38
Hi Dunc, It is pretty green - looks like something going on with stars as well... John
Title: Re: M8 Lagoon Nebula, May 2017 France
Post by: MarkS on Jul 04, 2017, 00:05:19
You have some very good data there but the Lagoon looks over-saturated and the background looks greenish.  Re-process the stacked image and I'm sure you'll produce an excellent result!

Mark