Archway to the Light
Double Rainbow arch with anti-crepuscular rays converging towards the Sangre de Cristo Mountains north of Santa Fe, New Mexico.
Archway to the Light
A brilliant double rainbow frames bright rays of light during a summer rainstorm in Santa Fe, New Mexico. This rainbow displays some interesting atmospheric optics phenomena that relate to the way sunlight interacts with raindrops and the effects clouds have on shadowing some of the rays from the sun. Standing in front of these impressive arcs felt like entering a gateway into another world.
The Story Behind the Photograph
Beginning in early July, the afternoon skies start to come alive with drama in Northern New Mexico. Thunderstorms form on late afternoons in July and August. This is perfect for rainbow photography! The low sun angle in the west coupled with rain showers bunched up along the Sangre de Cristo mountains to the east are excellent conditions to see rainbows.Read More
Photographing rainbows requires an acute awareness of rapidly changing weather and lighting. When it looks good, you have to move fast and get in good position. The light and rain do not wait for anyone.
Ideal conditions are localized areas of rain separated by clear skies with direct sunlight and no clouds to diffuse the sunlight. On summer afternoons I keep my eye out for these conditions. If things look promising I head out to locations where the sun is at my back and rain is falling off in a direction 42-degrees from my shadow.
On this particular afternoon, I noticed a golden glow of light outside underneath indigo storm clouds. I call this golden glow “rainbow light.” During a rainbow, there is an enhancement of light reflected back towards the viewer inside the arc of the primary rainbow.
When I saw the “rainbow light.” I knew I just needed to reposition myself, so I was at the rainbow angle of 42-degrees. The next step was to find an interesting foreground to compose a photograph of the rainbow. I promptly grabbed my gear and hiked out on a local trail into the correct angular position amongst a classic New Mexico landscape of juniper and piñon trees.
As I reached the correct angle, a brilliant full double rainbow filled the sky in front of me! The two rainbows were full across the horizon forming a stunning archway of brilliant colors. Inside the arches, the light was very bright. Beautiful rays of dark and light converged to a point in the center of the rainbow arcs to the east.
From my vantage point, it looked the entrance gate to paradise.
This time it worked out great. I was glad that I acted when I saw the initial golden “rainbow light” and went out looking for rainbows.
The Science Behind the Photograph
There are interesting optics phenomena in this photo. First, there is a double rainbow. In between the primary and secondary rainbow, the sky is dark. The sky is very bright inside the arc of the primary rainbow. There are rays of light converging on the eastern horizon, away from the sun.
Refraction, dispersion, and reflection of light come into play in the formation of the rainbows. Cloud shadows and perspective can explain the converging rays of light.
You can learn more about how rainbows form, and how to find them by checking out this overview article. Yes, you can predict where rainbows will be with just a little understanding of how they form and what angles to see them.Read More
Some fun facts about rainbows include:
- Each person sees a different rainbow.
- The shadow of your head is at the center of the rainbow.
- You can often see your shadow very far away and at the center of a rainbow.
- The primary rainbow is seen at a 42-degree angular radius from the shadow of your head.
- The secondary rainbow is seen at a 51-degree angular radius.
- The light forming the secondary rainbow reflects twice inside the raindrop, the light for the primary only reflects once inside the raindrop. This is why the order of colors in the secondary bow is reversed from the primary bow.
- The primary rainbow and secondary rainbows are formed from raindrops located in different areas of the sky.
- The rays that form the primary rainbow that we see are those rays that hit the top part of the raindrop.
- The rays that form the secondary rainbow that we see are rays that hit the lower part of raindrops, which are different from the raindrops that form the primary bow.
- The dark band between the primary and secondary bow is due to total internal reflection of light that cannot exit the raindrop at angles between 42-degrees and 51-degrees. This is referred to as “Alexander’s Dark Band”, after Alexander of Aphrodisias, who first described the effect in 200 AD.
- Rainbows do not exist in a particular location, they are angular phenomena, not a spatial one. A rainbow created by water droplets very close to you will look the same as a rainbow formed from the distant rain. Sorry, there is no “end of the rainbow” at a particular place.
Afternoons, when the sun is low, are usually the best times to see rainbows. In order to see a rainbow, you need to be located between a rain shower and the sun. The sun needs to be direct, not diffused by clouds. Learn more here about the correct angles to see rainbows.
Limited Edition Prints
Archway to the Light
(40 x 60 inch print shown here for scale)
“Archway to the Light” (c) Ed MacKerrow / In Light of Nature. ( 8625:5724, 3:2, 20170930__DS_4698_AU )