Printer Friendly

A useful DSLR camera modification.

Having decided to begin digital imaging of stellar spectra with a DSLR camera and after initially obtaining disappointing results, I wondered if removing the infrared blocking filter would improve the blue as well as the red end sensitivity of the CCD sensor? In theory it should, so I purchased a Canon Rebel 300D with the IR blocking filter removed, and took comparison spectra of Vega through this and a Canon EOS 400D (unmodified). I used a Rainbow Optics Star Spectroscope, 200 lines/mm, at the prime focus of my 0.3m Newtonian reflector, a drift time of 20sec across the field of view at ISO400, RAW image setting for each camera, on 2010 Nov 15.


The answer to the question is yes; removing the infrared blocking filter does improve the spectral sensitivity of the CCD sensor at both the blue and red end, as seen from the results. This has interesting implications for deep sky astrophotography and I encourage people to have a go.

Jack Martin


COPYRIGHT 2011 The British Astronomical Association
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2011 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Observers' Forum
Author:Martin, Jack
Publication:Journal of the British Astronomical Association
Article Type:Brief article
Geographic Code:4EUUK
Date:Apr 1, 2011
Previous Article:The owl nebula--M97.
Next Article:Exhibition Meeting and Ordinary Meeting, 2010 June 26: held at the Old Royal Naval College, Greenwich, London SE10.

Terms of use | Privacy policy | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters