Astronomical PhotographsMichael A. Covington
Author, Astrophotography for the Amateur and other books
All pictures Copyright 2004, 2005, 2006, 2007 Michael A. Covington.
All of these pictures, including the film images, have been processed digitally in standard ways.
Saturn and its satellite Enceladus, March 2007. 8-inch f/10 telescope, 2× Barlow, ToUCam Pro video camera. Stack of the best 1200 out of 1500 frames, processed with RegiStax. The region of Enceladus was processed separately from the rest of the picture because of the great difference in brightness between satellite and planet.
Lunar eclipse of 2004 October 27. Film astrophoto, processed digitally. Stack of two images on Elite Chrome 100 taken at the prime focus of my Celestron 5.
The Andromeda Galaxy. Stack of 5 film exposures taken in 2002, all on Elite Chrome 200, all with a Nikon 300/4 ED IF AF lens; they total about 2 hours of exposure. Digitized and processed in 2007.
Nebula IC 4628 and nearby star clusters in Scorpius. Stack of three film exposures taken in 2003, digitized and processed 2007. Nikon F3 body, Nikon 300/4 ED IF AF lens wide open, Ektachrome E100GX, exposures about 7 minutes each.
Orion in hydrogen-alpha light. Canon EOS 20Da DSLR, 105-mm f/2.8 lens, B+W 091 red filter. Despite being presented in color, this is really a black-and-white picture. Not all the nebulae in it are red. What is crucial is that, at this deep red wavelength, there is almost no light from streetlights. Accordingly, I was able to take this picture under magnitude 4.5 skies.
The Veil Nebula in Cygnus, an ancient supernova remnant. It's blue in this DSLR image (Canon 300D, 8-inch telescope at f/6.3), because the DSLR picks up Hβ and O-III emissions that color film does not record.
The Orion Nebula (M42). Stack of five 30-second exposures with Canon EOS 20Da camera, taken in moonlight as a quick test of the camera.
North America Nebula in Cygnus, a digital view. Canon XTi camera, Canon 300-mm f/4 lens, stack of four 3-minute exposures taken under a dark country sky.
The actual image comprises 10 megapixels, sharp all the way to the corners, and would make a fine poster-sized print. It may be the most detailed celestial image I've ever taken.
North America Nebula in Cygnus as seen by Ektachrome film, taken in 2003. 15-minute exposure with Nikon F3 body and 180/2.8 ED IF AF lens wide open. This is one of my most popular images and has been displayed as a 24×36-inch print.
Orion Nebula through an ordinary Canon DSLR (XTi) as opposed to the extra-red-sensitive 20Da. Single 6-minute exposure, Canon 300/4 lens at f/5.6, ISO 400, at a dark-sky site. Note diffraction spikes around bright stars, caused by the edges of the lens diaphragm.
The Double Cluster in Perseus (NGC 869 and 884). Stack of 3-minute exposures with Nikon 300-mm lens on Canon Digital Rebel body.
Omega Nebula (M17). Stack of five 3-minute exposures with Canon Digital Rebel (300D), 8-inch telescope at f/6.3.
M31, the Andromeda Galaxy. Stack of three 6-minute exposures with Canon Digital Rebel, Nikon 300-mm f/4 lens at f/5.6 with lens mount adapter.
What my telescope looks like, as of early 2007. Left to right: piggyback autoguider (lens similar to SBIG eFinder but homemade, on SBIG ST-V imager), Meade LX200 telescope, 8×50 finder, Canon 300-mm f/4 lens, Canon XTi (400D) camera body with angle finder.