The Trinity Test: First Atomic Explosion Through a Photographer's Lens

On July 16, 1945, the world entered the nuclear age at 5:29:45 a.m. Mountain War Time. In the Jornada del Muerto basin of New Mexico, the first atomic bomb—code-named "The Gadget"—was detonated. The explosion was captured by a team of photographers, most notably Berlyn Brixner, whose cameras recorded unprecedented images. These photographs, restored over 20 years, are featured in Emily Seyl's book Trinity: An Illustrated History of the World's First Atomic Test. Below, we explore key questions about this historic event and the photography that documented it.

1. What exactly happened at 5:29:45 a.m. on July 16, 1945?

At that precise moment, the world's first atomic bomb—a plutonium implosion device—was detonated atop a 100-foot steel tower in the New Mexico desert. The explosion unleashed a blinding fireball, turning night into day. The blast created a massive shockwave, a mushroom cloud, and a heat so intense that it melted the desert sand into green glass, later named trinitite. This test, code-named Trinity, marked the culmination of the Manhattan Project and ushered in the nuclear age. The bomb's yield was equivalent to about 21 kilotons of TNT. The event was observed by scientists, military personnel, and photographers stationed in bunkers several miles away.

2. Who was Berlyn Brixner and what was his role in photographing the test?

Berlyn Brixner was a photographer for the Manhattan Project, stationed in the North 10,000 photography bunker. He was one of the few people instructed to look directly at the blast—through welder's glasses—and track the fireball with his cameras. Brixner operated two Mitchell movie cameras mounted on a turret, with his head inside the turret to aim and follow the explosion. His footage became the best visual record of the Trinity test. Los Alamos scientists used these images to make precise measurements of the explosion's effects, such as the fireball's growth rate and temperature. Brixner's calm professionalism under extreme conditions ensured that the scientific value of the footage was maximized.

3. What cameras were used and how did they capture the explosion?

The photography effort deployed 52 cameras in various bunkers, but only 11 produced satisfactory images. Brixner's station used two Mitchell movie cameras and a high-speed Fastax camera. The Fastax camera, shooting through a thick glass porthole, captured the first milliseconds after detonation—less than a hundredth of a second—showing a translucent orb bursting from the darkness. The Mitchell cameras recorded the fireball's evolution over a longer period. The footage revealed details invisible to the naked eye, such as the initial sea of energy unfurling silently, then the violent rise of a multicolored fireball atop a twisting column of debris. These cameras were carefully synchronized with the detonation timing to ensure precise scientific data.

4. How did the explosion look visually according to the footage?

The footage shows the detonation beginning with a blinding flash—a sea of energy unfurling across the basin. In less than a hundredth of a second, a translucent orb appears, expanding rapidly. Then, as the brightness fades, a wall of dust rises around a shape-shifting, multicolored ball of flames. This fiery cloud shoots skyward atop a twisting stream of debris, forming the iconic mushroom cloud. The colors ranged from purple to orange to red as the fireball cooled. The camera captured intricate details—spikes, rings, and turbulence—that scientists analyzed to understand the physics of nuclear explosions. Brixner's footage preserved the moment in ultra-slow motion, allowing repeated study of the fireball's behavior, including its growth rate and the formation of the stem and cap.

5. How successful was the overall photography effort at Trinity?

Out of 52 cameras set up around the test site, only 11 produced satisfactory images. Many cameras failed due to the intense heat, shockwave, or timing errors. However, the footage that succeeded was invaluable. Brixner's Mitchell and Fastax cameras delivered the best results, used for decades by scientists to measure blast effects and validate nuclear weapons models. The photography effort was considered a huge success on balance because the key data—fireball growth, yield estimates, and shockwave propagation—were captured. The failure of other cameras taught valuable lessons for future tests. The restored images, published in Seyl's book, offer a striking new view of the test's first seconds.

6. What is the book 'Trinity: An Illustrated History' and why is it important?

Written by Emily Seyl with contributions from Alan B. Carr, the book Trinity: An Illustrated History of the World's First Atomic Test (University of Chicago Press, 2026) presents hundreds of photographs from the Manhattan Project. These images emerged from a 20-year restoration effort to digitize and preserve original negatives, many of which were deteriorating. The book not only shows the test itself but also the people, equipment, and landscape around it. It offers a comprehensive visual record of the Trinity test, providing context for one of history's most consequential experiments. The author's access to newly uncovered archival materials makes this a definitive resource for historians and the public alike.

7. How did scientists use the footage to measure the explosion's effects?

Scientists at Los Alamos used the footage to make exacting measurements of the fireball's behavior. By timing the expansion frame-by-frame, they calculated the yield of the bomb—about 21 kilotons. They measured the fireball's temperature from its color and brightness, and tracked the shockwave's speed. The high-speed Fastax footage allowed analysis of the first few milliseconds, revealing the implosion dynamics. The images also helped study the formation of the mushroom cloud and the distribution of radioactive debris. These measurements were critical for understanding nuclear weapon performance without the need for further tests. The footage was reanalyzed for decades, and the new high-resolution scans in Seyl's book have enabled even more precise calculations.