Every year for the last 10 (or so) years I’ve traveled to the Grand Canyon during the Southwest summer monsoon to photograph lightning. Not only have I captured hundreds of lightning strikes and lived to tell about it (yay), I’ve learned a lot. A couple of years ago I added an article sharing my insights on photographing lightning to my photo tips section. With lightning season upon (or almost upon) us here in the United States, I’ve updated my article with new images and additional info. You can still find the article (with updates) in my Photo Tips section, but I’m re-posting it here in my regular blog feed as well.
Read the story of this image at the bottom of this post, just above the gallery of lightning images.
Let’s start with the given that lightning is dangerous, and if “safety first” is a criterion for intelligence, photographers are stupid. So combining photographers and lightning is a recipe for disaster.
Okay, seriously, because lightning is both dangerous and unpredictable, before attempting anything that requires you to be outside during an electrical storm, it behooves you to do your homework. And the more you understand lightning, how to avoid it and stay safe in its presence, the greater your odds of living to take more pictures. Not only will understanding lightning improve your safety, a healthy respect for lightning’s fickle power will also help you anticipate and photograph lightning.
Lightning is an electrostatic discharge that equalizes the negative/positive polarization between two objects. In fact, when you get shocked touching a doorknob, you’ve been struck by lightning. The cause of polarization during electrical storms isn’t completely understood, but it’s generally accepted that the extreme vertical convective air motion (convection is up/down circular flow caused when less-dense warm air rises, becomes more dense as it cools with elevation, and ultimately becomes cool/dense enough to fall. Convection is also what causes bubbling in boiling water. Convection in a thunderstorm carries positively charged molecules upward and negatively charged molecules downward. Because opposite charges attract each other, the extreme polarization (positive charge at the top of the cloud, negative charge near the ground) is quickly (and violently) equalized: lightning.
With lightning comes thunder, the sound of air expanding explosively when heated by a 50,000 degree jolt of electricy. The visual component of the lightning bolt that caused the thunder travels to you at the speed of light, over 186,000 miles per second (virtually instantaneous regardless of your distance on Earth). But lightning’s aural component, thunder, only travels at the speed of sound, a little more than 750 miles per hour—a million times slower than light. Knowing that the thunder occurred at the same time as the lightning flash, and how fast both travel, we can compute the approximate distance of the lightning strike. At 750 miles per hour, thunder will travel about a mile in about five seconds: Dividing the time between the lightning’s flash and the thunder’s crash by five gives you the lightning’s distance in miles; divide the interval by three for the distance in kilometers. If five seconds pass between the lightning and the thunder, the lightning struck about one mile away; fifteen seconds elapsed means it’s about three miles away.
The 30 (or so) people killed by lightning in the United States each year had one thing in common with the rest of us: they didn’t believe they’d be struck by lightning when they started whatever it was they were doing when they were struck. The only sure way to be safe in an electrical storm is to be in a fully enclosed structure or metal-framed vehicle, away from open windows, plumbing, wiring, and electronics.
While there’s no completely safe way to photograph lightning, it doesn’t hurt to improve your odds of surviving to enjoy the fruits of your labor. (Unfortunately, photographing lightning usually requires being outside.) Most lightning strikes within a six mile radius of the previous strike. So, if less than thirty seconds elapses between the flash and bang, you’re too close. And since “most” doesn’t mean “all,” it’s even better to allow a little margin for error. Thunder isn’t usually audible beyond ten miles—if you can hear the thunder, it’s safe to assume that you’re in lightning range.
But if you absolutely, positively must be outside with the lightning crashing about you, or you simply find yourself caught outside with no available shelter, there are few things you can do to reduce the chance you’ll be struck:
Photographing lightning at night is mostly a matter of pointing your camera in the right direction with a multi-second shutter speed and hoping the lightning fires while your shutter’s open—pretty straightforward. Photographing daylight lightning is a little more problematic. It’s usually over before you can react, so without a lightning sensor to recognize lightning and click your shutter, success is largely dumb luck (few people are quick enough see it and click). And using a neutral density filter to stretch the exposure time out to 20 or 30 seconds sounds great in theory, but a lightning bolt with a life measured in milliseconds, captured in an exposure measured in multiple seconds, will almost certainly lack the contrast necessary to be be even slightly visible.
Lightning Trigger: The best tool for the job
Most lightning sensors (all?) attach to your camera’s hot shoe and connect via a special cable to the camera’s remote-release port. When engaged, the sensor fires the shutter (virtually) immediately upon detecting lightning, whether or not the lightning is visible to the eye or camera. With many lightning sensors from which to choose, before I bought my first one I did lots of research. I ended up choosing the sensor that was the consensus choice among photographers I know and trust: Lightning Trigger from Stepping Stone Products in Dolores, CO. At around $350 (including the cable), the Lightning Trigger is not the cheapest option, but after many leading lightning-oriented photo workshops, I can say with lots of confidence that lightning sensors are not generic products, and the internal technology matters a lot. Base on my own results and observations, the Lightning Trigger is the only one I’d use and recommend (I get no kickback for this). On the other hand, if you already have a lightning sensor you’re happy with, there’s no reason to switch.
I won’t get into lots of specifics about how to set up the Lightning Trigger because it’s simple and covered fairly well in the included documentation. But you should know that of the things that sets the Lightning Trigger apart from many others is its ability to put your camera in the “shutter half pressed” mode, which greatly reduces shutter lag (see below). But that also means that connecting the Trigger will probably disable your LCD replay, so you won’t be able to review your captures without disconnecting—a simple but sometimes inconvenient task. You also probably won’t be able to adjust your exposure with the Lightning Trigger connected.
The Lightning Trigger documentation promises at least a 20 mile range, and after many years using mine at the Grand Canyon, I’ve seen nothing that causes me to question that. It also says you can expect the sensor to fire at lightning that’s not necessarily in front of you, or lightning you can’t see at all, which I will definitely confirm. For every click with lightning in my camera’s field of view, I get many clicks caused by lightning I didn’t see, or that were outside my camera’s field of view. But when visible lightning does fire somewhere in my composition, I estimate that the Lightning Trigger clicked the shutter at least 95 percent of the time (that is, even though I got lots of false positives, the Lightning Trigger missed very few bolts it should have detected). Of these successful clicks, I actually captured lightning in at least 2/3 of the frames.
The misses are a function of the timing between lightning and camera—sometimes the lightning is just too fast for the camera’s shutter lag. In general, the more violent the storm, the greater the likelihood of bolts of longer duration, and multiple strokes that are easier to capture. And my success rate has increased significantly beyond 2/3 since switching from a Canon 5DIII to Sony mirrorless (more on this in the Shutter Lag section).
The Lightning Trigger documentation recommends shutter speeds between 1/4 and 1/20 second—shutter speeds faster than 1/20 second risk completing the exposure before all of the secondary strokes fire; slower shutter speeds tend to wash out the lightning. To achieve daylight shutter speeds between 1/4 and 1/20 second, I use a polarizer, with my camera at ISO 50 and aperture at f/16 (and sometimes smaller). Of course exposure values will vary with the amount of light available, and you may not need such extreme settings when shooting into an extremely dark sky. The two stops of light lost to a polarizer helps a lot, and 4- or 6-stop neutral density filter is even better with fairly bright skies (but if you’re using a neutral density filter, try to avoid shutter speeds longer than 1/4 second).
Lightning is fast, really, really fast, so the faster your camera’s shutter responds after getting the command from the trigger device, the more success you’ll have. The delay between the click instruction (whether from your finger pressing the shutter button, a remote release, or a lightning sensor) and the shutter firing is called “shutter lag.”
The less shutter lag you have, the better your results will be. The two most important shutter lag factors are:
In addition to a lightning sensor and fast camera, you’ll need:
Getting the shot
Lightning is most likely to strike in or near the gray curtains (clearly recognizable as distant rain) that hang beneath dark clouds. In addition to visible rain curtains, the darkest and tallest clouds are usually the most likely to fire lightning. Here are a few more points to consider:
Do as I say (not as I do)
Be aware that electrical storms can move quite quickly, so you need to monitor them closely. Sometimes this simply means adjusting your composition to account for shifting lightning; other times it means retreating to the car if the cell threatens your location. No shot is worth your life.
About this image
On the first evening of last year’s second Grand Canyon Monsoon photo workshop, Don Smith and I took the group to Point Imperial for a sunset shoot. Based on the forecast we had little hope for lightning, but one thing I’ve learned over the many years of photographing the monsoon here is that the forecast isn’t the final word. We got another reminder of this that evening.
The view from Point Imperial is both expansive and different from other Grand Canyon vistas, stretching east across the Painted Desert and north to the Vermillion Cliffs. As the group made their way down to the vista platform, in the corner of my I thought I a lighting strike far to the north. A second bolt confirmed my discovery and soon we had the entire group lined up with cameras pointed and triggers ready.
With everyone in business, I set up my tripod and attached my Lightning Trigger to my Sony a7RIII. Since this lightning was close to 30 miles away, maybe farther than any lightning I’ve tried to photograph, so I hauled out my Sony 100-400 GM lens and zoomed in as tight as I could. I didn’t have to wait long to confirm that my Lightning Trigger would catch strikes this distant—it didn’t hurt that these were massive bolts, many with multiple pulses and forks.
Everyone was thrilled, so thrilled that it didn’t immediately register that the storm was moving our direction. I started at 400mm, but by the time I captured this frame I was just a little more than 100mm. That’s still a pretty safe distance, but with night almost on us and another cell moving in from the east, we decided to take our winnings and go home.
One final note: If you check my exposure settings, you’ll see that my shutter speed here was .4 seconds, well outside the 1/20-1/4 second range I suggest. But if you look at the other settings, you’ll see that I’d opened up to f/7.1, and had cranked my ISO to 400, an indication that twilight was settling in. Successful lightning photograph is all about contrast, and the darker the sky, the better the bolt stands out, even in a longer exposure. Had we stayed past dark (and lived), we could have jettisoned the Lighting Triggers and used multi-second exposures.
Join Don Smith and me in our next Grand Canyon Monsoon Photo Workshop
Read my article in Outdoor Photographer magazine, Shooting the Monsoon
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