PetaPixel

Friday Morning in Strobe Alley

Paying a visit to Doc Edgerton's high speed photography lab

strobealley

“Ya wanna see Edgerton’s lab?”

Now, asking a photographer if he would like to see the workspace of the guy who made all those iconic stop-action images of impossibly fast-moving objects was like asking a short-order cook if he’d like to see where they invented the ham and cheese omelet.

But coming from Cheryl , one of my former students and a sergeant with the MIT Police Department, I knew those few words were ripe with possibility.

So, one lovely Friday morning not all that long ago, my colleague and pal Heratch and I dropped off a dozen fresh, hand-cut donuts at MIT PD (I mean, how often do you get to deliver donuts to a bunch of cops?). We then joined Cheryl and her boss, Chief John DiFava, for the quick walk over to Strobe Alley, Doc Edgerton’s suite of classrooms and labs in a building just east of the MIT dome.

Harold E. “Doc” Edgerton didn’t invent the strobe light or the electronic flash, and he wasn’t the first photographer or scientist to explore the potential of using strobes to stop rapid motion on film. But his genius transformed the strobe from a laboratory curiosity into an important tool for science, industry and photography. In their biographical memoir of Edgerton published in 2005 by the National Academy of Sciences, J. Kim Vandiver and Pagan Kennedy laid out his legacy in a paragraph:

“He made flashing light cheap and portable, and found endless applications for it, from the airport runway to the office copy machine. But despite his importance as an innovator, Edgerton is best known for the photographs he took: the drop of milk exploding into a crown, a bullet hovering beside an apple, an atomic blast caught the instant before it mushroomed, a smudge that might have been the flipper of the Loch Ness Monster. His strobe photographs illustrated scientific phenomena in a way that was instantly understandable to millions of people.”

After joining MIT’s faculty in 1932, one of his earliest contributions to the science of photography was the introduction of argon gas into electronic flash tubes, a technical achievement that enabled brighter, faster flash output than had previously been available. Indirectly, this development would contribute far more to the esthetic of photography and to the popular visual perception of time and motion.

Many of his experiments with high-energy, high-speed strobe lights took place in the room in which I was now standing, a room that looked more like a gadgeteer’s crowded basement workshop than a prominent point on the star map of the history of photography.

Vandiver and Kennedy described the place:

“The hallway echoed with the report of gunshots. Flashes jumped across the walls. Boxes spilled wires, capacitors, barnacled wood. By contrast, other wings of MIT seemed downright sterile. Strobe Alley, the hallway that cut a line between Edgerton’s labs, sucked visitors in and invited them to become part of the action. To make his lair even more inviting, Edgerton hung displays all along the hall: photographs, framed bits of equipment, buttons to push. [Former student and side-scan sonar expert Marty] Klein, who wandered into Strobe Alley as an undergraduate in 1961, loved the tantalizing smell of the place. It reminded him of the junk shops in lower Manhattan…’”

_DSC0041

The pushbuttons, photographs and showcased exhibits of equipment are all still much as they were when Edgerton walked the hallway. On my left, I had immediately noticed a very old device sitting on a workbench, looking like a prop from a 1950’s sci-fi flick. It also bore a passing resemblance to the Speedotron power packs that I used for years in my commercial photography business. But this thing was bigger, blacker and scarier looking with its knobs, dials, toggles and ammeter, and was plastered with various labels warning of the dangers of working alone with high voltage. I understood what that was all about.

Years ago I was working in a studio while another photographer was shooting a model. My friend, perhaps distracted by the beautiful woman on the set in front of him, decided to straddle a 2400 watt-second Norman pack and rearrange its cables in order to change the power ratio to the flash heads he was using.

imageBrazenly ignoring the standard practice of turning the pack off and dumping the energy stored in its capacitor before disconnecting a flash cable, he flicked his eyebrows at the model once or twice and then yanked hard on one of the thick black leads. The pack logically responded by arcing and exploding in a flash of yellow light and white smoke between his legs.

When the roiling mushroom cloud dissipated against the ceiling a few seconds later, there he stood, frozen stiff, still holding the cable in his hand and covered from head to toe with soot and pulverized electrical insulation. The misshapen power pack lay on its side a few feet away from where it had been. Fortunately, his injuries were limited to a bruised ego.

My thoughts were brought back to the here and now by a bearded, casually-dressed guy welcoming us from the opposite corner of the room. Dr. Jim Bales is the assistant director of what is now known as the Edgerton Center. We introduced ourselves, and  thanked him for inviting us. Then he asked  “What did you bring to shoot?”

_DSC0003

Cheryl had told us earlier that we were not just going to be able to see the lab, but that there was a good chance we would actually see a demonstration of how Edgerton made his stop-action photographs of bullets piercing various objects. We were to bring along our cameras, tripods, and some “targets”.

Heratch and I had mulled this over for quite some time. “Ya know…” he started with the same two words that he has opened countless conversations with in the past, “…a Boston Cream donut might make a pretty good target.” I agreed wholeheartedly, and I now presented to Dr. Bales with a perfect specimen of our city’s indigenous donut carefully packaged in a small white box tied with string.

“Oh, another cream donut. That’s what everybody brings. You’d be surprised”, he said. “The bullet goes in and out and the donut absorbs all the energy and just sort of folds around it before any of the cream squirts out. We’ve never really gotten a very good shot of a bullet going through a cream donut.”

“Right, right, of course, that’s pretty fascinating.” I tried to make it sound as if I had never really believed the donut would work, but in that moment the door to the enormous warehouse of topics that I don’t know the first thing about (but venture a comment on anyway) opened just a crack. Heratch shot a look at me; he knew that I had been planning to title this essay “Time To Shoot The Donuts”.

_DSC0034Jim showed us around the lab a bit and introduced us to the other scientist in the room, Dr. Bob Root. Bob told us that his company, Prism Science Works, designed and built the small strobe unit we would be working with. Its flash duration was astonishingly short, somewhere in the neighborhood of one-third of a microsecond, literally faster than a speeding bullet.

Jim and Bob explained how a small microphone, positioned a few inches from the target, captures the sound of the shock wave (a miniature sonic boom) that precedes a supersonic projectile and fires the strobe as the bullet enters, is inside of, or exits the target, depending on where the mic is actually placed.

With the room completely darkened, a camera with its shutter held open captures the infinitesimally brief burst of light and the scene that it illuminates; in one-third of a microsecond, a bullet and any ejected debris from the target appear to be stopped in mid-flight.

“And the thing that you shouldn’t forget” Bob continued, “is that your eyes are also a camera. Once you get used to what is going on, you will actually see the bullet stopped in midair the same way that your camera will record it.” The principle is the same as what happens when a strobe light is turned on in a darkened night club; fluid movement on the dance floor turns into what looks like a really bad Quicktime movie.

Jim told us that he would start by firing at the thin edge of a playing card, attempting to capture an image of a bullet tearing the card in half. He asked for a volunteer to help him sight down the bore of the rifle. Skip Hoyt, another photographer friend of Cheryl’s and an acquaintance of Jim’s from MIT’s Lincoln Labs, stepped forward to help.

_DSC0013

Jim stuck a Joker in the folds of an old felt blackboard eraser resting on a stand in the center of the room, and then knelt down behind the .22 caliber target rifle strapped along the length of a gray wooden sawhorse positioned next to a workbench on the far wall of the lab. With Skip’s help, he positioned it perfectly relative to the immobilized rifle.

_DSC0032

On the other end of the “range”, a gaffer’s tape-covered length of iron pipe welded to a stand appeared to be lined up to catch the bullet. From rifle muzzle to coffee can, our shooting gallery measured less than 8 feet in length. Anyone scoring Maggie’s Drawers in here would have some explaining to do to whoever happened to be in the room next door.

Doc Edgerton’s safety issues had been even more serious; for many of his pictures he had used a .30 caliber military rifle firing heavy bullets at nearly 3 times the speed of sound.

“The first thing you should be asking, Skip, since you’re standing in the line of fire, is ‘where’s the bolt?’” Jim stood up from sighting-in the rifle. The bolt is part of the rifle’s loading mechanism and contains the firing pin. Shaking his pants pocket he said “Don’t worry, the bolt’s right here.”

At that point we arranged our digital SLR’s in a tripod-mounted scrum a couple of feet away from the playing card. The squarish white strobe, about the size  of a lunch box, was perched on a light stand to the left of the cameras. A small black box containing the microphone was positioned slightly to the left of and below the playing card, poised to trip the strobe as the bullet tore the card in half. The sawhorse holding the rifle was to the right of the whole arrangement, about 3 feet away from where my camera was and where my right ear would soon be.

We all fumbled with our cameras, setting the exposure mode to “M” and the shutter speed to “B”. Jim shut out the lights, plunging the room into absolute darkness. He then tripped the strobe by clapping his hands once near the microphone so we could determine the proper aperture to set on our lenses.

“I always wanted a clapper strobe”, Heratch quipped, beating everyone else in the room to the obvious.

Finally, it was show time. Jim distributed headphones and protective eyeglasses to everyone as we all crouched down in a little huddle behind our cameras, right index fingers poised  on shutter releases. Being closest to the rifle, I felt the nerve endings tingling on the right side of my face as Jim got into position. After checking to make sure everyone was ready and where they were supposed to be, he started his very deliberate countdown.

“OK. Bolt’s in the pocket. Eyes and ears on? Loading. Loaded. Lights out.

Remembering what Bob had said about trying to see the bullet with my eyes, I stared into black space at where I knew the card was.

“Shutters open.”

The sound of 5 camera shutters snapping open came faintly through the protective headphones.

“3…2…1…BANG!

_DSC0016

For the briefest instant imaginable, I saw the perfectly bisected white card brilliantly illuminated less than 4 feet in front of my face. Suspended in space on its left side was a jagged field of bits of torn paper, and, perfectly frozen against the blackness just beyond, the unmistakable oblong shape of a dull gray bullet. I saw it with my eyes, and a few moments later I saw it again on my camera’s LCD screen.

I’ve never appreciated digital photography more than in that moment. The instant digital preview appearing on the back of our cameras was the one fundamental thing that differed from Doc Edgerton’s experiments 70 years earlier. How hard it must have been for him to have to wait while his film was processed and printed! How lucky we were! We all knew it, and the room erupted in spontaneous, amazed laughter.

“Shutters closed. Lights on. How’d we do?” Surely Jim had seen this reaction a thousand times in his years at Strobe Alley, but he smiled nonetheless as he checked the thumbnails on each of our cameras.

_DSC0018

_DSC0017

We repeated the process 7 or 8 more times, firing at more playing cards and each other’s business cards. At one point Heratch, realizing he didn’t have a business card with him, started looking through his wallet for a photo of his family. Jim stopped him.

“Sorry. We don’t do pictures of people or pets. No ex-wives or girlfriends. It sends the wrong message.”

The last target we used was a particularly plump green grape from somebody’s lunch perched on top of a plastic film canister. Jim’s first shot was a little low, resulting in an interesting but less-than-spectacular image. He adjusted the height of the next grape by placing it on a wad of FunTak, and the ensuing explosive impact left us all wiping grape juice off our faces and lenses while marveling at the images we had made.

_DSC0023

_DSC0025

As I packed up my gear, I looked up above the general area where the targets had been placed and saw stalactites of dried Jell-O, egg, peanut butter and God knows what else splattered like a three-dimensional gravity-defying Pollack on the ceiling.

While researching Edgerton and his work for this essay, I was surprised to learn that he had once lived down the street and around the corner from where I was living at the time. It reminded me of the night I sat just a table away from Philip Morrison, a principal physicist on the Manhattan Project and a colleague of Edgerton’s at MIT, dining with friends on chicken kabobs at a local Greek joint.

My own dinner companions that evening were mildly interested when I tried to explain who the lively old guy in the wheelchair was, but, frankly, seemed more impressed with the nice tomato sauce on their fluffy white rice than by the fact that the guy who helped drop the big one on Japan was sitting right next to us.

The devastating effects of the atom bombs dropped on Hiroshima and Nagasaki in 1945 haunted Morrison, who went on to become a leading proponent of nuclear nonproliferation. Edgerton, meanwhile, directing his expertise and scientific curiosity toward the same subject, produced unforgettable high-speed photographs recording the awesome, apocalyptic beauty of H-bomb tests in the 1950’s and 60’s with a camera of his own design.

Rapatronic_Picture_003

Until Morrison became a minor TV celebrity with his popular PBS series The Ring Of Truth, neither of these guys were easily recognizable as they lived their extraordinary lives in our midst. Yet the work that they did became an indisputable part of the iconography of the twentieth century.

Doc Edgerton died on January 4, 1990 after suffering a heart attack at the MIT Faculty Club. “Papa Flash”, as his friend and collaborator Jacques Cousteau had nicknamed him, was 86 years old. “I performed CPR on him”, Cheryl mentioned quietly as we left Strobe Alley that Friday morning.

I just looked at her, not quite knowing what to say. But afterwards I found something that he liked to say, and I haven’t been able to get it, or the rare privilege of having spent a couple of hours seeing firsthand what few before him had even imagined, out of my mind.

“If you don’t wake up at three in the morning and want to do something, you’re wasting your time.” 

I haven’t been sleeping quite as much ever since.

Harold Edgerton 20


 
  • Joey Duncan

    Awesome article.

    “Its flash duration was astonishingly short, somewhere in the neighborhood of one-third of a microsecond, literally faster than a speeding bullet.”

    this is really fast.

  • Ralph Hightower

    Seeing that photo of the grape reminds me of the web page of old, “Innocent Inanimate Objects” where various objects, such as a bottle of soda, and others things were photographed being shot by a high-powered rifle.

  • johngf

    Brilliant principle. Instead of controlling the light on the sensor with the shutter, control the light itself.

  • SBPhoto

    You can simulate Edgerton’s work, at least with the droplets, by shooting really close to the subject, and the flash set on 1/128th power (so only one capacitor is firing at a time) this reduces the duration of the flash to 1/30,000th of a second or so. Manual exposure at 1/fps. Start the drip and go for it.