British Astronomical Association
Supporting amateur astronomers since 1890

Secondary menu

Main menu

BAA Gallery Picture of the Week
Image search

Messier 76


Expand image

About this observation
David Davies
Time of observation
13/12/2014 - 08:39
Observing location
Harlton, Cambridge, UK
QSI 583
6 hours
Like This Image

Once you have taken your filtered images in narrowband you have the decision as to how to compile them to best show the object.  In this case, David tried both a Hubble palette (red, green, blue is derived from sulphur, hydrogen and oxygen, respectively) and the less frequently seen HOS palette (red, green, blue is derived from hydrogen, oxygen and sulphur, respectively). He found that the Hubble palette gave a predominantly blue image from which it was difficult to tease out any detailed structure. By contrast the HOS palette yielded a green/yellow and red image and more of the detail could be teased out by tweaking the colour balance in Photoshop.  So that was the version David chose to present.

Six hours of data were captured, in 20 minute subs, equally split between hydrogen-alpha, oxygen III and sulphur II.  Equipment details are:

Telescope: 254 mm Newtonian with Tele Vue Paracorr at F/4.5.
Camera: QSI 583wsg with Astrodon 3 nm narrow band filters.
Off-axis guiding by SX Lodestar.
Focussing by Scopefocus using Nebulosity for image capture
Mount: EQ6 controlled by EQMOD

Image processing by Pixinsight and Photoshop.

Copyright of all images and other observations submitted to the BAA remains with the owner of the work. Reproduction of the work by third-parties is expressly forbidden without the consent of the copyright holder. For more information, please contact the webmaster.