Rainbows are a favorite subject for landscape photographers, but the lesser-known phenomena known as ‘moonbows’ – rainbows created by moonlight – aren’t as easy to find. . However, once photographers know where to look, they are easier to predict.
California photographer Brian Hawkins has been capturing Yosemite National Park’s famous moon arch for 12 years. His obsession with these lunar rainbows began in 2011, long after he first photographed Yosemite.
A mechanical engineer by trade, Hawkins spends his time planning his photographs of rainbows at night in Yosemite by creating 3D simulations. For this spring, Hawkins has identified three optimal windows to capture lunar arcs: April 14-18, May 13-17, and June 11-15.
Hawkins analyzes the data and details the best time to capture moon arcs on its website where, in addition, it keeps weather forecasts up to date so that photographers can be fully aware of their real chances of capturing incredible photos.
“Lunar arcs are simply rainbows that occur at night, using light from the moon instead of the sun,” explains Hawkins. “They are just as common as daytime rainbows, but they often go unnoticed because human vision is not as sensitive in low light. Moon arcs can be found in a predictable source of water spray which gets a lot of moonlight, like the huge waterfalls in Yosemite National Park.
Hawkins says lunar arcs can occur whenever moonlight shines on water droplets in the air at the correct angle to an observer.
“In practice, it’s easiest to see them when the moon is nearly full on a clear night while standing near the mist of a waterfall. I recommend watching when the moon is less than two days away from being 100% full, if you’re lucky enough to capture it, the moon arcs during a supermoon are even more intense.
However, simply planning to arrive in Yosemite on the dates and times indicated by Hawkins does not guarantee that a person will see the moonbows. Observers will still need ideal conditions to photograph the colored bands above the misting water.
“In addition to an almost full moon, a clear sky is a must. Even thin clouds can diffuse moonlight so that a moon arc does not occur. A calm night can also limit the drama of moonbows, as it often helps to have wind to carry the mist from the waterfall higher in the air.The most important aspect of photographing moonbows is knowing where to position yourself.The light of the moon is refracts and reflects through water droplets at the “rainbow angle” of 42 degrees, so a photographer must know where and when to be to achieve this angle to the water and the moon “, he explains.
“My background in aerospace engineering helped me develop a method to visualize this using 3D modeling in 2012, and in 2018 I started sharing this information on a dedicated website, Yosemite Moon Bow, so others can find out when to attend the Moonbow at popular locations in Yosemite.
With over a decade of moonbow experience in Yosemite National Park, Hawkins has become the ultimate resource for all things moonbow.
“I first photographed lunar arcs in 2011,” says Hawkins. “I can’t remember how I first heard about it, but I was already in love photographing Yosemite and it was just another magical phenomenon that happens in this special place.”
“The idea for this short film came to me in 2016,” he continues. “I wanted to do something that no one had done before. Others have made moonbow videos using timelapse, but for me the fast motion never really captured the real experience. So, I wanted to show people what it was really like to witness the moon arcs, because our eyes would actually see them. Plus, it doesn’t hurt that I appreciate the technical challenge this movie created. I started capturing these real-time video clips in 2016, and over the years have made two to three visits every spring, except in 2020 when the park was closed.
Shooting real-time video in the dark of night hasn’t always been easy. Until recent advances in camera technology, a film like this would have been impossible.
“The film was shot with Sony mirrorless cameras; mainly the A7S II and more recently the FX3. I also used a selection of quick lenses. High ISO sensitivities were required and significant noise reduction was needed during editing,” he says.
“I knew that to make this film truly unique, I had to think outside the box and capture angles that weren’t so well known,” Hawkins continues.
“I experimented with countless angles. Among them were deliberate choices to include people, buildings, cameras and other light sources to illustrate the nighttime setting. My favorite angle was from Glacier Point. At this distance, careful calculation had to be made to determine when to be there, as the lunar arc is only present for 15 minutes. I believe I was the first person to photograph the Glacier Point moonbow. I also really enjoyed hiking the Upper Yosemite Fall trail with my gallery friend Ansel Adams, fellow landscape photographer, Brittany Colt. We had to stay up until 3am to capture the compound moon arch with Half Dome in the background.
It’s easy to see that years of research and hard work have paid off. Hawkins’ film offers an incredible view of a rarely captured phenomenon in one of the most photographed places in the world. Still, Hawkins will never tire of photographing Yosemite National Park.
“Yosemite is one of those rare places that never seems to run out of ways to challenge and inspire. In addition to my enjoyment of its natural splendor, it also appeals to my passion for science as I research about Yosemite phenomena such as the lunar arcs. All of this leads to the joy of being able to share my art to show the world how unique and beautiful Yosemite National Park is.
You can find more information about Brian Hawkins on his website, his Moonbow prediction website, YouTube and Instagram.
Picture credits: All photos by Brian Hawkins