Swansea Astronomical Society Blog

When red, green and blue filters are used to capture monochrome images which are then assigned to the appropriate colour channel in an RGB colour image, the additive properties of the three primary colours are being used:



M1 with the Hubble Palette

This image of Jupiter was captured on the evening of December 24th with a DBK camera, an 11" SCT and a 1.5x Barlow:

During 2010 SAS member Andrew Sprott has produced software that has been published in the SPA magazine 'Popular Astronomy'. Andrew has worked with Steve Wainwright on the programs with Steve working on specifications, algorithms and testing, but Andrew has done the hard, skilled work of coding it up into useable programs.
Popular Astronomy, April-June issue 2010

This article is about a program called Dark-Frame-Scaler, essential for frame-accumulating videography of deep-sky objects.

Popular Astronomy, September-December issue 2010

This article is about a program called 'CAP' (Colour Alignment Processor) that can be used to construct RGB colour images from monochrome images taken through red, green and blue filters. It can also be used to correct for atmospheric chromatic dispersion that produces red and blue edges to colour planetary images.
A new version of this program called AUTOCAP has now been completed. This version is completely automatic. Look out for this in 2011.
Whenever you see on this site a H-alpha solar image showing both details of the solar disk and prominences, it is highly likely that Andrew Sprott's 'Solar Layers' program will have been used to combine images exposed differently for the disk and prominences. Similarly images of the Orion nebula showing both details of the trapezium and the large clouds of luminosity in the rest of the nebula, may well have been processed in Andrew's 'FIC', (Flexible Image Combine) software.
Andrew is now working on ideas for a new computer environment in which software can be developed.

It is possible to get quite good images of the Moon by using afocal techniques (photographing through the eyepiece). The choice of eyepiece can be important as is the level of zoom used with the camera to avoid vignetting. These things can be improved with experience. There are a number of afocal mounting devices (often called digiscoping mounts) that allow a digital camera to be attached to an eyepiece to facilitate the afocal process. Here is a simple device attaching a digital compact camera to a 25mm eyepiece that has been placed on a 5" Maksutov:

On Saturday 18th, using a newly discovered method of daytime aligning a Synscam AZ GOTO mount, the Moon and then Jupiter were located in a daytime sky. The Moon, of course, was visible, but Jupiter could not be seen with the naked eye in the blue sky.
A DMK camera was placed at the prime focus of a 5", f/5 Newtonian and two ends of the Moon were imaged.

Copernicus area


Tycho area


Daytime Jupiter through a 3x Barlow

Look carefully and you will see some of Jupiter's moons.


A candid shot ... hmmm !




Nikki Mackin

An 80mm Apo refractor was placed on a Merlin Mount and aligned on the Moon in the daytime sky as it rose through the trees:

On the night of the 16th the first snowfall came, followed by a patch of clear Sky. I mounted the Skymax 127 Maksutov on a Synscan AZ GOTO mount:

This image is composed from 10x 30s exposures and 15x 90s exposures:
Visible are M42/3 and NGC1977


Keith Davies

Last night, (13th) SAS member Chris Playle went to a dark observing site at Mewslade where he observed 20 Geminids and 2 fireballs over a two hour period.

Rachael Sweeting and Jo Rosney-Lee observed for about 45 min from Llanelli starting at 10-30 (13th). They observed 6 Geminids and one of them was a fireball

Colin Miles observed the Geminids (14th) between 11-10pm and 11-30pm from Llanon. During this time, he saw 7 Geminids.

Colin Elphic and Don Morgan spent several hours at Fairwood and observed a large number of Geminids over their observing session

I saw 2 Geminids during a 5 minute sortie into the garden at 11-00pm (14th)

Steve Wainwright

I used a DMK camera fitted with the lens assembly from a x2 Barlow and H-alpha & Ca K-line PST solar scopes.

I used a H-alpha PST and a Ca K_line PST with a DMK camera fitted with the lens assembly of a x2 Barlow and an 80mm Apochromatic refractor fitted with a 1000 Oaks glass solar filter.

Prof Mike Edmunds gave his first rate one man dramatisation of 'Sir Isaac Remembers' in the Waterfront Museum today at 2-30pm:

23 x 1 min exposures and 4 x 1 min 40s exposures were captured and stacked in Deep-Sky Stacker. The resulting 16bit Tiff image was post processed in Photoshop to produce this image of M82, the cigar galaxy:

This narrowband image of the flame and horse head region was taken using a Atik 314L CCD camera with an ultra narrowband Hydrogen Alpha filter. The scope was a 80mm achromatic refractor and was guided using Guidemaster software with Shoestring Astronomy Guide USB Guideport Adapter. The image has been built up from 7 x 15 minute subs, dark-frame and bias-frame corrected and post processed in Photoshop CS5.

This image constitutes a "Work in Progress" as more colours channels will be added when possible.



Nikki Mackin

Deep Sky Astronomers have two lights to plague their efforts.