Milky Way from Dead Horse Point
Milky Way from Dead Horse Point, Dead Horse Point State Park, Utah
One of the great pleasures of learning night photography is the way it opens up new possibilities in familiar locations. I had photographed from Utah’s Dead Horse Point many times at both sunrise and sunset, but it wasn’t until a sunrise shoot in October 2017 that I suddenly realized that at astronomical dusk in the fall, the galactic center, the very brightest part of the Milky Way, would appear directly above the Gooseneck of the Colorado River 2,000 feet below. Fortunately, the weather was clear. I returned that night and set up with a gnarled Utah juniper as my foreground. I liked the composition, which I had used at sunrise more than half-a-dozen times, but I knew it would be challenging to photograph at night, for two reasons. The first concerned depth of field. At the wide-open aperture I would need to use on my Canon 16-35mm f/2.8L III lens, an image focused on the stars would show a blurry tree. To achieve full depth of field I would need to use focus-stacking. The second reason concerned the image noise caused by using a high ISO. To control noise, I used an iOptron SkyTracker Pro, a star-tracking camera mount that moves the camera in time with the stars. That allowed me to keep the stars round while using a long exposure, which in turn allowed me to use a lower ISO. To further reduce noise, I planned to use a Photoshop utility called Stack Mode>Median.
The first step was to align the axis of rotation of the star-tracker with the axis of rotation of the Earth by pointing the tracker precisely at Polaris, the North Star. With polar alignment accomplished, I shot four identical exposures for the sky at 2 minutes, f/2.8, ISO 1600. Then I turned off the tracker. With the camera still focused at infinity, I made four identical exposures for the land, 3 minutes, f/2.8, ISO 6400. Then I focused on the tree itself and made four more identical exposures, again at 3 minutes, f/2.8, ISO 6400. Once I returned home, I used RegiStar software to perfectly align the star images, then used RegiStar’s equivalent of Stack Mode>Median to stack the images, reduce noise, and output a single image of the stars and Milky Way. I then used Photoshop’s Stack Mode>Median utility to reduce noise in each group of land images, then used Photoshop’s Auto-Align and Auto-Blend utilities to merge the sharp parts of the two land images into one uniformly sharp image. Finally, I used Photoshop to combine the sky and land images into a realistic whole. Learning night photography had enabled me to create an image of an iconic location that looked like nothing I had captured there before.