Few natural phenomenon can cheer people up faster than the beauty of a rainbow. Getting great images of one is a challenge, they are difficult to predict and constantly changing, occurring due to a specific set of conditions. These tips will help you photograph rainbows when they appear, and get great results when processing your rainbow pics in the digital darkroom. As a bonus, I promise I will refrain from any “pot o’ gold” jokes along the way.
How, When, and Where to Find a Rainbow
For a rainbow to appear you need three ingredients; light, suspended droplets of water, and be in the right spot to see it. Despite popular belief, leprechauns are not required (strike 1, that promise didn’t last long).
The perfect situation for a photographer is when the sky in front of you is dark with rain clouds, you have sun and clear sky at your back, and are within a couple of hours of sunrise or sunset. Because rainbows appear due to a very specific way in which light interacts with rain drops, the best time to see a rainbow is usually in the early morning or late afternoon. Ideally you want scattered showers or very localized storms, if clouds completely cover the sky you are not likely to see one.
With the right conditions, a rainbow will appear about 40 degrees up from the horizon (about half of the way to looking straight up). The height of the sun above the horizon is the biggest factor in a rainbow’s appearance. The closer it is to the horizon, the higher the top of the bow extends into the sky. As the sun gets lower the color of the bow changes, with the blues and greens becoming less visible.
So now that you have tracked down the wily and elusive rainbow, it’s time to start taking photos of it!
Rainbow Photography Tips and Techniques
Unless you have a very wide-angle lens, it is difficult to capture a full rainbow in one image. “Angle of view” is a measure in degrees of how much of a scene you can capture in one shot, based on the focal length of your lens, and the size of your camera’s sensor. In other words, what your camera can see through your lens.
Rainbows generally stretch across an angle of view of 84°. On a full frame camera, you need roughly a 19mm or smaller (wider) lens to capture this view in the frame. This can pose a problem for smaller sensor cameras, especially those on smartphones, which may not be able to go wide enough to include the arc in a single frame.
What if I don’t have a lens capable of going that wide?
Look at the scene and decide if including the full bow is necessary. You should compose your image well with thoughtful choices of what to include, but there is no rule that you must have the full bow.
You can also compose a “Long Lens Landscape”, using a telephoto to zoom in and show just part of the bow. These can be very compelling and creative shots, as the band of color will be a dominant part of the image. Remember that color alone is often not enough to carry a composition, you still have to make good artistic choices.
You can also try your hand at shooting a panorama, taking multiple shots to capture the full scene. This is a great way to capture sweeping views of stormy skies and rainbows. Many cameras feature a panorama mode that will automatically create a panoramic image as you pan. Personally, I prefer the DIY method of taking single shots, each overlapped about 25% with the previous shot, and stitching them together later in Photoshop.
And if you just have to have that full bow, you can of course buy a new lens (any excuse for new photo gear, right!?!)
“And My Settings Should Be…?”
Rainbows are an optical phenomenon, they are not a physical structure. They are not at a certain distance from you, thus the difficulty in finding the pot of gold (strike 2). As you move, it appears to move with you, staying at exactly the same place in your field of view (sun, clouds, and rain permitting). So you can’t focus on one, and you can’t meter off of one. The key is, shoot the scene, not just the rainbow!
Some Starting Points
- Mode: Aperture Priority
- Aperture: f13-18
- ISO: 100-200
- Exposure Compensation: Based on tone of sky. Dark sky -2/3 (or -0.7), Bright white sky +2/3 (or +0.7)
- White Balance: Auto
- Shoot, check your histogram, and adjust accordingly
- And, of course you are doing this all off a nice stable tripod, right? ;)
The conditions that produce rainbows also produce tough photography conditions. Low light, wind blowing, and parts of the scene cloaked by clouds to create areas of deep shadow and high contrast. All while threatening to rain on you and your precious gear.
As with any image, start by thinking of what you want in focus in the shot. I usually shoot in aperture priority, since light can rapidly change in the stormy conditions that produce rainbows. I select my aperture and ISO as I would for a typical landscape photo opportunity, in the f13-18ish range, with a lower ISO to cut noise.
When you choose your depth of field and focal point, choose physical items in the scene that you want in focus in your photo, like clouds or mountains. Rainbows do not have distinct edges that you have to get tack sharp. Make sure the physical elements in your scene fall within your depth of field, especially if you are including dominant foreground elements.
Because the sky is the main feature in rainbow images, pay attention to the tones of the clouds. Dark skies will need minus exposure compensation, usually in the -2/3 (or -0.7) range, while a very bright hazy sky will need positive compensation, usually +2/3 (or +0.7) or more. I may also shoot the scene as an HDR, which will even out the contrast in the scene, as well as make your rainbow’s colors more vibrant. Leprechauns are typically fair-skinned, so expose them accordingly (c’mon, I’m Irish, you have to give me a pass on that one).
Try a Circular Polarizer
Since we know that mother nature doesn’t always provide perfect conditions, a circular polarizing filter can cut the glare of white skies and bring out a rainbow’s color. But, since the light in a rainbow is mostly polarized, it can also make the rainbow disappear! Oddly, most people will not believe you took a great rainbow shot if the rainbow is invisible. Rotate your filter until the colors intensify, just make sure it is properly lined up to evenly apply the effect, otherwise your sky may look “bruised” on one side!
If you aren’t happy with what came out of your camera, these are some recommended adjustments when you develop your rainbow shots in Lightroom, particularly for dark or flat images. Remember, each image is different and these are only guidelines. So, be sure to experiment with your settings.
Camera Calibration Panel
- Canon 5D Mark III
- Tamron SP 15-30mm f/2.8 Di VC USD Lens
- Tamron SP 70-200mm f/2.8 Di VC USD
- Tamron SP 150-600mm f/5-6.3 Di VC USD
- Gitzo GT3543LS Systematic Carbon Fiber Tripod (Long)
- Really Right Stuff BH-55 Ball Head with Full-Size Lever-Release Clamp
- Haida 150 x 150mm Circular Polarizer Filter
- Haida 150 Filter Holder Kit for Tamron 15-30mm Lens