Star Trails Behind Double Arch

Circumpolar star trails spinning behind Double Arch at Arches National Park, Utah, as the waning gibbous Moon lights the arches toward the end of the sequence. The Big Dipper is streaking into frame at top right from behind the butte at right, while Jupiter is the bright object at top left streaking down into the scene. During the shoot, other photographers were lighting the Arches with spotlights but this did not affect my shoot, as my foreground came from near the end of my shoot long after they had all left, and I had natural illumination from the Moon to light the Arches.

This photo composite is a stack of 160 frames taken over 2.5 hours from 9:30 to midnight, starting in moonless darkness, then brightening as the Moon rose in the last hour of the shooting, lighting the sky and arches. The nearest arch casts its shadow onto the distant arch, with its shadow shape matching the other arch. The frames were stacked with Star Circle Academy’s “Advanced Stacker Plus Actions” for Photoshop using the Long Streaks effect. The foreground comes from a stack of 8 frames for noise reduction, taken toward the end of the shooting with the moonlight illumination. An additional frame taken a couple of minutes after the last star trail frame adds the short unstreaked stars at the head of the trails.

Each exposure was 45 seconds at f/2.8 and ISO 3200 with the Canon 6D and 14mm Rokinon lens. Dark frames taken at the end of the night (8 stacked in Mean combine for a master dark) were also subtracted from each of the foreground and star trail stacks, which reduced noise speckling.