Perseid Meteor Shower over Turret Arch
Perseid Meteor Shower over Turret Arch, Arches National Park, Utah
The Perseid meteor shower is always one of nature’s best fireworks displays. At its peak, in a dark-sky location, you may be able to see as many as 50 or 60 meteors per hour. In 2018, a new moon occurred on August 11, at the beginning of the three-day period when the shower peaks, providing completely dark skies and great viewing conditions all three nights.
I had photographed the Perseids on two previous occasions, but I wanted to make an even better image than I had before, with more and brighter meteors. As with my previous efforts, I wanted my composition to include the radiant, the point in the sky where the meteors appear to originate. For the Perseids, the radiant lies in the northeast corner of the constellation Perseus the Hero. After much map study and review of study frames I’d made on previous trips, I decided to photograph the Perseids over Turret Arch in Arches National Park. To capture more meteors, I decided to shoot for three nights in a row, then combine all the meteors I photographed into one image. To capture brighter meteors, I mounted a 24mm f/1.4 lens on the first of the two cameras I used. The key to capturing bright meteors is a large maximum aperture, measured in terms of the area of aperture when the lens is wide open. Meteors only last a second or two, so the shutter speed is irrelevant so long as it is longer than the meteor duration. A 24mm f/1.4 lens offers a good balance of large maximum aperture and wide angle of view. Longer focal-length lenses can provide apertures with a larger area, but they have a narrower angle of view, so many meteors will rocket past the edge of the frame. That means they can’t be included in the final composition. I attached a 16mm f/2.8 lens to a second camera to capture meteors that traveled farther from the radiant before becoming visible, as well as the full length of exceptionally long meteors. The aperture of a 16mm f/2.8 lens has only one-seventh the area of a 24mm f/1.4 when shooting wide open, but the 16mm lens has a much wider angle of view.
The weather in Arches National Park was consistently hot, hazy, and smoky, but the skies were mostly free of clouds. The temperature broke the 100 degree mark every afternoon, but the nights were very pleasant. I photographed until 3 a.m. the first night, then until astronomical dawn (5 a.m.) on the last two nights. On all three nights, I shot back-to-back exposures, 20 seconds, f/1.4, ISO 3200 for the 24mm lens, 30 seconds f/2.8, ISO 6400 for the 16mm lens. In total, I shot 3780 frames that I hoped would contain meteors. I shot additional images of the land and the background sky using a multi-row panorama kit and 35mm f/1.4 lens. At each camera position I made multiple exposures, then used Photoshop’s Stack Mode-Median utility and the equivalent procedure in RegiStar to reduce noise in the land and sky. After sifting through all 3780 frames, I identified 49 frames containing meteors that were bright enough to include in the final composition. The digital darkroom work consumed about three days, but I believe the result was worth the effort.