This Sunday night’s Geminid meteor shower is shaping up to be worth an all-nighter. South Dakota already enjoys a relative surplus of open sky free from light pollution, and Geminid arrives at an advantageous time on the lunar calendar. Dark skies will be out there for the watching, or photographing.
Shooting celestial events can get very technical, but it is possible for a novice to get some nice shots. With the right equipment, some luck and a little knowhow, you can be a Gemini monster like Skelesaurus.
Steve Babbitt, a professional photographer and photography professor at Black Hills State University, offered some tips on how even photographic greenhorns can capture Geminid in all her glory.
1. Get away from city lights. The light of the moon can also interfere. Fortunately, this weekend’s waxing crescent moon will set before Geminid’s projected peak. You should definitely shoot away from the moon, regardless of where it is in the sky. The shower’s radiant point — somewhere in the vicinity of the Gemini the Twin constellation — should reach its zenith around 2am local time. The astronomy experts recommend orienting 40 to 60 degrees away form the radiant point to catch a more horizontal trailing effect on the comet dust.
2. Use a sturdy tripod. For making long exposures, “an inexpensive tripod will probably not suffice, especially if there’s the least bit of wind,” says Babbitt. Any movement will result in blur. “Oftentimes, I’ll tie a rope around the neck of my tripod and and tie a rock or a brick to the end of it to weight it down and hold it firmly to the ground.”
3. Bring plenty of battery power. “It takes a lot of extra juice to make those long exposures. Having a backup battery is also handy.”
4. Focus to infinity. This is easier to do in daylight. “What I do is during the day, I put the lens on manual focus, then focus on something like a distant mountain and then use some painter's or gaffer's tape to hold the focus ring in place.”
5. Use a cable, or remote, shutter release. Pressing the shutter button will shake the camera at the start of your exposure. Cable or remote releases are available at different price points depending on capabilities. The cheapest simply open the shutter. More expensive models can be programmed to take set exposures at regular intervals. (Some cameras can as well, elimiinating the need for a remote release.)
6. Set your camera on the widest aperture possible (the smallest f-stop number) and a high ISO. Babbit recommends going as wide as an f 1.8, with an ISO of 3200 to 6400. You can make up for smaller apertures with longer exposure time, but if you expose too long, you’ll start capturing star movement (not just meteor movement), and the stars may look more like orbs than perfect points. Using extremely high ISO’s will capture more light but can result in visual noise like blue or red speckles.
7. Experiment.Try an exposure time of 20-30 seconds, and check the results on your LCD screen. Then you may want to adjust accordingly.
8. Don’t forget about composition. “The really good images of the night sky almost always include something in the foreground — the distant hills, some trees, a lake. If there’s water or something that the stars can reflect into, it makes for a very compelling image.”
With some luck, those eight steps should get you some good shots, if not the astro-pageant of the century. At its peak early Monday morning, the Geminid will shower the skies with up to 120 meteors per hour, or about two per minute, which is pretty good. Unless you manage to photograph a rare peak Leonid shower, most photos you come across of many meteors streaking across the sky are created by overlaying multiple exposures, shot from the same spot, in Photoshop.
If you have the software and some basic knowhow, you can do this too. All you have to do is keep your camera in exactly the same position and take a bunch of shots at the same exposure over a length of time, then layer them in Photoshop. Here’s where the sturdy tripod becomes invaluable. One tiny move, and your photos won’t line up.
Using the same principle (and Photoshop), you can also create a time-lapse video — a perfect topic for an SDPB space photography listicle in time for next year's Perseid meteor shower.
As always, remember to share your starscapes with SDPB. Your correspondent will be out there with coyotes scanning the horizon. Hopefully the cosmos smiles a little on us all.