Astrophotography: Piggybacking Your DSLR and Telescope
“Piggybacking” refers to the process of mounting your camera and lens on a telescope.
Basic piggybacking does not just allow photographs to be taken through your telescope as it would through a long lens. The camera/telescope combination helps guide your camera as the stars move from east to west. You basically attach your camera to the body of telescope and it goes along for the ride, capturing images as it moves.
There are a number of ways to affix your camera to the telescope. Some “do-it-yourselfers” will use clamps available at Home Depot or what they already have around the house. There are also specialized attachments available for most telescopes with a standard fitting that is compatible with any camera’s tripod attachment.
To track stars accurately, you must use an equatorially mounted telescope and align it so that its polar axis aims as close to the celestial pole as possible. For those new to astronomy, that is the point in the sky near Polaris (i.e. the North Star) around which stars appear to rotate as Earth spins on its axis.
Setting your camera
With regard to camera settings, you can check out my prior post in this series. In many cases, finding the best ISO rating, exposure time, and aperture will involve a bit of trial and error, as the lighting and other environmental conditions can influence your shots. Thankfully, digital cameras make it easy to view your images and quickly make adjustments.
With regard to subject matter, many amateur photographers use piggybacking to capture images of the Milky Way, including its well-known constellations and glowing clouds of interstellar gas. The best part — if the piggybacking is done correctly and the mount tracks well, you can simply lock the shutter open, sit back, and let the camera do the work.
For more advanced astrophotography, you can also use your DSLR set up to shoot through your telescope, using the scope instead of the camera lens. However, that is a discussion for a future post.