This video discusses equivalent exposures. What they are and how to use them when shooting in the field.

Equivalent exposures are combinations of aperture, shutter speed and ISO that produce the same level of brightness in an image. In other words, they are different exposures that create an equal amount of light. To make an equivalent exposure you need to adjust your camera’s settings proportionally in opposite directions to get the same amount of light.Creating equivalent exposures gives you more freedom to use the creative benefits of apertures, shutter speed and ISOs. They are useful when you want to adjust your aperture to make creative changes in the amount of depth-of-field, or to change the amount of motion with the shutter speed, or adjust your ISO in low light settings.

This episode of The Science of Photography also includes a bonus PDF detailing Equivalent Exposure Scales.

Whitney comes to us with degrees in biology, computer science and robotics. While at university and as part of several robotics startups, she wrote code to control robots and their various sensors, including cameras. She also trained experts on how to use these robots in a variety of settings, from search and rescue workers operating in a disaster, to astronauts training on the seafloor. She worked for several years at an optical spectrometer company where she programmed spectrometers and learned the physics behind light and color at their most fundamental levels. Later, she taught Photoshop and graphic design as an adjunct professor. Yet, it wasn't until after she became a mom that she picked up a camera for the purpose of creating art. This unconventional career path allows Whitney to bring to bear a diverse technical background that promises a unique depth to her work, while her skills as an educator allow her to explain it in a way that remains accessible.