Posted on September 22, 2019
Every August for the last seven years, good friend and fellow pro photographer Don Smith and I have done a Grand Canyon Monsoon photo workshop where we attempt to, among many other things, photograph lightning. I say “many other things” because Grand Canyon doesn’t need lightning to be spectacular. And even without lightning, the monsoon storms that build above the canyon most afternoons add beautiful clouds, rainbows, and sunsets to the magnificent vistas. (We also try to include a Milky Way shoot.) But as nice as all that other stuff is, most people come for the lightning. Don and I do our best to establish realistic expectations, because as reliable as the summer monsoon is in the American Southwest, nothing weather related is a sure thing.
This year I got a reminder of that fact by watching the weather forecasts leading up to our workshops. Each year in the weeks before first workshop’s start date, I regularly (obsessively) monitor the Grand Canyon weather forecast. This is a futile exercise that does nothing but add stress because no matter what the forecast is, I get anxious. No lightning? Oh no! This year’s monsoon is a dud (a “nonsoon”). Lots of lightning? Oh no! All the good stuff will be over before we get there. Sigh.
Coming into this year’s workshops, Don and I had done 12 (two per year for six years). For the first few years, I’d estimate that in about half, everyone in the group captured multiple lightning strikes (in some groups the number of successes approached or exceeded 100). In many of the less successful workshop, a few people got lighting and a few didn’t. And a few were a complete shutout. But the last two years had been great, with everyone in both groups getting multiple strikes.
Part of this recent success I attribute to just plain good luck, and part I attribute to experience—Don and I have gotten better at preparing the groups, teaching lightning photography, troubleshooting Lightning Trigger and camera problems, reading and responding to the conditions, and simply knowing where to be and when to be there.
This year’s first workshop would start on July 31, but as July wound down, each day’s forecast called for blue sky. Blank. Blue. Sky. Maybe our run of good luck was about to end. Fire up the anxiety engines. Compounding my stress was the realization that this would be our 13th monsoon workshop. And we had 13 participants—I’m not a particularly superstitious person, but still…. (We normally cap our groups at 12, but a small administrative hiccup resulted in an extra enrollee.)
But, to make a long story just a little shorter, we needn’t have worried. On the day our first workshop started, Mother Nature flipped the lightning switch and by the end of the third day (of five), everyone in Group 1 had their lightning. Phew. As it turned out, that group ended up with multiple lightning opportunities. Halfway there….
The second group had to wait until the fourth day, and only got one good shot at it, but theirs was one of the most spectacular lightning storms I’ve ever witnessed (Lightning Explosion, Oza Butte)—both for its intensity and its proximity.
Don and I usually use the day between workshops to “recharge” (pun unavoidable), but at dinner that evening we’d been monitoring our (fantastic) lightning app, My Lightning Tracker Pro, we saw that lightning was firing nearby and just couldn’t resist going out on our own.
Picking the lowest hanging fruit, we ended up at easily accessible Mather Point. The show was well underway when we arrived, but didn’t need to wait long before our Lightning Triggers started firing. I captured a dozen or so frames with lightning that evening, some with multiple bolts, but the unique, circuitous path followed by one I share above was my favorite.
I recently rewrote the lightning explanation portion of my Lightning Photo Tips article. As you’ll read below, lightning always follows the easiest path to resolve its polarity discrepancy, so I wonder what atmospheric machinations caused this serpentine bolt.
A lightning bolt is the atmospheric manifestation of the truism that opposites attract. In nature, we get a spark when two oppositely charged objects come in close proximity. For example, when you get shocked touching a doorknob, on a very small scale, you’ve been struck by lightning.
The primary process at work in an electrical storm is convection, the circular, up/down flow that happens when heat is applied to a fluid. As air warms, it becomes less dense and rises. The rising air cools with altitude and becomes more dense, causing it to sink. But the sinking air warms as it loses altitude, eventually rising again, and the cycle continues…. (Convection is also the process behind the bubbling of boiling water.)
Convection’s up/down flow creates turbulence knocks together airborne molecules, striping their (negatively charged) electrons. Lighter, positively charged molecules are carried upward in the convection’s updrafts, while the heavier negatively charged molecules remain near the bottom of the cloud. Soon the cloud is electrically polarized, more positively charged at the top than it is at the base.
Extreme polarity can also happen when a negatively charged cloud base hovers above the positively charged ground. Either way, nature resist this charge disparity and tries to resolve it as fast as possible: a lightning bolt.
Nature always finds the easiest path. If the easiest path to electrical equilibrium is between the cloud top and bottom, we get intracloud lightning; if it’s between two different clouds, we get intercloud lightning. A cloud-to-ground strike occurs when the easiest path to equilibrium is between the cloud and ground.
With lightning comes thunder, the sound of air expanding explosively when heated by a 50,000 degree jolt of electricity. The visual component of the lightning bolt that caused the thunder travels at the speed of light, over 186,000 miles per second (from the human perspective, that’s 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 the speed both travel, we can estimate distance of the lightning strike. At 750 miles per hour, thunder will travel about a mile in about five seconds: Dividing the number of seconds 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.
One of the things I love most about photographing lightning at Grand Canyon is the ability to do it in relative safety. With a few notable exceptions (see Lightning Explosion above), most of the lightning we photograph is at least 10 miles away, distant enough that we rarely hear thunder. I won’t pretend that any lightning photography is completely safe because the safest place to be in an electrical storm is always inside. But standing on one Grand Canyon rim while waiting for lightning to fire on the other rim, as we did this evening, feels more like magic than madness.
Click an image for a closer look and to view a slide show.
Posted on September 12, 2016
I rarely shoot at Mather Point because I’m usually working with workshop students struggling to corral the extreme dynamic range of a summer sunrise there. But on this morning a couple of weeks ago, about half the group had congregated at the rail in near the Mather Point amphitheater, allowing me to set up my tripod and occasionally visit my camera. When it became clear that the clouds were setting up for something special, I prepared my composition, set my f-stop to f/18 (in the sunstar zone), and ready my graduated neutral density filter in anticipation of the sun’s first rays peeking out from behind Wotan’s Throne.
Knowledge is power
As with many of my images, I can trace this image’s creation to long before the shutter clicked. That’s because, whenever possible, I avoid arriving at a location without knowing at the very least when and where the sun will appear or disappear. In this case I was familiar enough with the Mather Point in August to know that the sun would rise between Wotan’s Throne and Vishnu Temple. But I needed to be more precise than that.
We’re living in an era of ubiquitous information, carrying mini computers with the potential to make virtually everyone an instant astronomical genius. Though my own workflow for computing sun/moon arrival/departure information was established long before smartphones, it amazes me both how easy the internet and smartphones have made preparation, and how few photographers do it.
I got a little head start because I studied astronomy in college for a few semesters (long enough to learn that the essential math would would wring the marvel from my mind), enough to have good mental picture of the celestial rotations and revolutions that determine what we see overhead and when we see it.
While I’m just geeky enough to prefer plotting all this stuff manually, for most people I recommend starting with one of the excellent apps that automate most of the process. Of the two apps I recommend, PhotoPills and The Photographer’s Ephemeris, I prefer PhotoPills because it seems more complete, but they’re both excellent.
If you’ve tried either of these apps and found them too complicated, don’t be discouraged—neither is so intuitive that you should expect to simply pick it up and use it. But each is logical and well designed, and I promise that the more you use it, the easier it will become. In other words, practice!
As with most things in photography, it’s best not to be trying to learn to predict the timing and position of the sun or moon when the results matter. Rather, I suggest that you plot tonight’s sunset from the park down the street, or tomorrow’s sunrise from your backyard. Figure out where and when the sun will set or rise, be there to check your results, and then figure out why it didn’t happen exactly as expected. You’ll be surprised by how quickly your predictions improve after repeating this process a few times. Once you feel comfortable with your ability to anticipate a sun or moon rise or set from home, it’s time to take the show on the road—pick a spot you know fairly well and apply your new knowledge there.
Working it out on the fly
For me, celestial preparation from the comfort of my recliner is only half the job. It’s great when I know exactly where I’ll be and when I’ll be there, but the reality of nature photography isn’t quite so simple. On a first visit to a new location, I often end up places I never imagined I’d be—Hmmm, I wonder where that road goes…, or, Gee, I bet the view from the top of that hill would be great…—often with no connectivity.
On location with no connectivity, I need to be able to figure out the celestial details with only the resources at hand. The two iPhone apps I’ve come to rely on most are Focalware (I couldn’t live without this app) and MotionX-GPS.
Using these two apps, plus my basic understanding of astronomical dynamics, I’m able to figure out everything necessary to plan a shoot. On this morning at Mather Point, I pulled out my iPhone and opened Focalware to determine the sunrise time and azimuth. I used the MotionX-GPS Measure tool to drop a pin at my current location, then stretch a line, at the angle of the sunrise azimuth, across the canyon until it intersected the horizon. That was all I needed—seeing that this sunrise line passed just to the right of Wotan’s Throne, I was able to set up the composition I wanted.