Astrophotography is often considered to be an inaccessible field to any but the most dedicated (and well equipped) photographers, but such is not necessarily the case. While expensive equipment certainly doesn’t hurt and is even essential depending on the magnitude of your target object, there are celestial sights that can be photographed with a camera even without the use of exotic or expensive equipment. One such target just so happens to be our nearest celestial neighbor, the Moon. Get a decent zoom lens or a spotting scope and adapter, and you could be in business!
(Note that one problem with such an approach is the inability to use exposure metering- this is one area where the prime focus method shines. If you happen to have a telescope you can link to a DSLR, assuming that you own a DSLR, then you might want to give this technique a try. Personally, I think that a DSLR or advanced point-and-shoot with a long zoom do a pretty good job of capturing the moon, at least for the casual astrophotographer.)
One difficulty, however, in attempting to photograph the Moon is its brightness, especially when using an afocal camera-telescope combination. An excellent compromise is the lunar eclipse, an event in which the Earth blocks the Sun’s light from reaching the Moon, as it gives you a visually striking target while not being so bright as to overwhelm your camera. (The reddish-brown color you see during a lunar eclipse is due to secondary sunlight reflected off the Earth.) Lunar eclipses occur more often than their solar counterparts, and certainly require less exotic equipment to cope with. Here are some pointers to keep in mind:
- Noise is your enemy. As any good photographer knows, the low-light conditions will demand use of high-ISO settings (or long exxposure times, which are unacceptable) for a given aperture setting, which will in turn increase the amount of noise in your photograph. While such noise is certainly annoying in normal photographic conditions, these off-color pixels will stand out against a black background. Gather as much light as possible, since this will allow you to use lower ISO or increase the shutter speed to combat vibrations and atmospheric distortions. If you intend to shoot under these conditions on a regular basis, you may wish to consider purchasing a digital camera with excellent high- ISO performance.
- Consider HDR techniques. Obtaining a good exposure may be chancy even with your camera’s light metering capabilities available. Shooting multiple pictures and combining the results may allow you to obtain a better final result than any single image would.
- As the world turns… Remember that the earth (and moon) move; its apparent motion works out to a distance that is approximately equal to its own diameter every hour. While this won’t matter for short exposure, the dimmer conditions prevalent during the eclipse will interfere with exposure times measured in significant fractions of a minute. This is where a computerized tracking mount could come in extremely handy, if you happen to have access to one.
- Find out when and where you need to be. If you’re going to photograph a lunar eclipse, then you need to be in the right place at the right time. Use this US Naval Observatory eclipse page to plan your forays!