Which three controls make up the exposure triangle in photography?

• A. ISO, Shutter Speed, Aperture
• B. White Balance, ISO, Exposure Compensation
• C. Shutter Speed, Aperture, Lighting
• D. Aperture, Focal Length, ISO

Answer: (A)

The exposure triangle is formed by ISO, shutter speed, and aperture. ISO controls the sensor’s sensitivity to light—lower ISO needs more light for a proper exposure but keeps noise low, while higher ISO requires less light but introduces more noise. Shutter speed determines how long the sensor is exposed to light; fast speeds freeze motion but let in less light, while slow speeds let in more light and can create motion blur. Aperture is the size of the lens opening; a wider opening (lower f-number) lets in more light and gives a shallower depth of field, while a smaller opening (higher f-number) lets in less light and increases depth of field.

These three settings work together to reach the correct exposure, so changing one usually means adjusting another to compensate. For example, in bright light you can lower ISO and/or use a smaller aperture or a faster shutter speed to maintain proper exposure. The other options aren’t part of the exposure triangle: White Balance deals with color temperature, Exposure Compensation is a separate control for brightness adjustments, lighting describes scene illumination, and focal length affects perspective rather than exposure.