Photography Exposure Triangle

I haven’t taken photos in a while before I took pictures of The Greasy Boys the other night. The Sony A700 DSLR and Sony f/1.4 50mm lens struggled to expose shots in the dimly lit venue. This got me thinking about the exposure triangle as it pertains to photography. What is this triangle?

The photography exposure triangle refers to the three essential elements that determine the exposure, or brightness, of a photograph. These three elements are:

1. Aperture – this refers to the size of the opening in the lens through which light enters the camera. A smaller aperture (represented by a larger f-number) will let in less light, while a larger aperture (represented by a smaller f-number) will let in more light.

2. Shutter Speed – this refers to the amount of time that the camera’s shutter stays open to allow light to enter the camera. A slower shutter speed (represented by a smaller number in the denominator, e.g. 1/30) will let in more light, while a faster shutter speed (represented by a larger number in the denominator, e.g. 1/500) will let in less light.

3. ISO – this refers to the sensitivity of the camera’s sensor to light. This is akin to the “speed” of film, such as 200, 400, 800, etc. ISO. A higher ISO will make the camera more sensitive to light, and therefore brighter, while a lower ISO will make the camera less sensitive to light, and therefore darker.

Together, these three elements determine the overall exposure of the photograph. Adjusting one of these elements will affect the other two, and it’s up to the photographer to find the right balance to achieve the desired exposure. For example, if you increase the aperture to let in more light, you may need to increase the shutter speed or decrease the ISO to avoid overexposure.

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