Astrophotography

In the entrance to the school science block there is currently an exhibition of astrophotography by Gavin James.  He took these pictures in his back garden in Marlborough in Wiltshire. 

The telescopes he uses are relatively modest refractors or reflectors, but mounted on a computer controlled motorised mount to track the stars as they move across the night sky.  The camera is a highly specialised (and pretty expensive) device with a relatively modest resolution, fitted with different filters to record different wavelengths of light.  His exposures can be 30 minutes or more long, but each image is actually a composite of multiple exposures, each using a different filter in front of the air cooled monochrome CCD, so the overall exposure used can run into hours (taken over several nights).  The images are put together using dedicated software, and then finalised in Photoshop.

You can see his images on his Flickr site, but the images on screen cannot do justice to the stunning, large prints hanging on the exhibition panels.  Apart from their scientific value (and each photograph is accompanied in the exhibition by detailed astronomical information provided by experts at Marlborough College) they are just beautiful images.