Capturing Trinity on camera

Photos helped scientists study the first nuclear explosion

July 5, 2022

Trinity Cameras (89 1015)[1] Opt
Trinity cameras Los Alamos National Laboratory

When J. Robert Oppenheimer, General Leslie Groves and the observers of the Trinity test conducted their clandestine nuclear explosion, data gathering was paramount to understanding the efficacy—or possible failure—of the Gadget. One of their most important methods of recording the test for future study was photography.

Photographs allowed the researchers to assess the explosion after the fact. They placed multiple types of cameras at differing distances from the explosion, and captured images at varying speeds. This helped the scientists determine the sequential rates of activity, the size of the evolving events and the force of the explosion.

Deep in the Bradbury Science Museum’s collections are prints of Trinity images, overlayed with text that identifies details about the explosion. Each image is marked with arrows to pinpoint an observation such as “The shock wave is moving out from the flame front.” Having such images of the event allowed the researchers to clarify the details of what happened through each stage of the explosion and understand the behavior of their tremendous creation.

Photography before Trinity

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Scientists used photos to study the Trinity test.

Photography was a critical research tool throughout Project Y. While developing the implosion method, high-speed photography became an essential tool for data gathering. The Instrumentation Group developed high-speed camera technologies and photography methods, including rotating-prism camera, high-explosives flash and flash x-ray techniques. Using these different methods, scientists could study the implosions’ timing and symmetry. Project Y staff also established Q-Site in October 1944, designing it for both flash photography and physical experiments. A small, wood-frame building served as the Q-Site dark room and shop. This is the only structure presently remaining at Q-Site, which is a part of the Manhattan Project National Historical Site in Los Alamos.

Recording the recorders

Camera Log
Researchers recorded extensive data about the cameras at Trinity.

The Project Y scientists were meticulous in recording data—not just through photography, but about photography. They not only gathered copious physical and visual data about the Trinity explosion, but they kept a detailed log of the multiple cameras at Trinity and their operations, like “shutter setting” and “exposure time.” The handwritten log also contains remarks about each camera’s results, such as “Overexposed, but shows ball of fire and branches.”

Interested all things Manhattan Project? Visit the Bradbury, explore the online collections and check out this month’s exhibit about the Trinity test at the White Rock visitor center.