Does Your Exposure Triangle Have to be Perfect?

Understanding the exposure triangle and the representation of the unique relationship between aperture, shutter speed, and ISO is important in filmmaking and in still photography. At Beverly Boy Productions, early cinematographers frequently ask us about the importance of the exposure triangle and how accurate it must be. In answering the question, “Does your exposure triangle have to be perfect?” a variety of potential descriptions can be offered.

We’re answering the common question, “Does your exposure triangle have to be perfect?” and more importantly, we’re explaining to you what the exposure triangle is and how the relationship between aperture, shutter speed, and ISO can be used to assist you in keeping control over the exposure of the images you take.

Does it have to be perfect? The short answer is, “NO!” 

What is the Exposure Triangle?

The exposure triangle is a visual representation of the relationship between aperture which controls the amount of light going through the lens, shutter speed which represents the control for the amount of time light hits your camera sensor, and ISO which represents a unique description of sensitivity to analog film.

Essentially, the exposure triangle is represented at the top by the shutter speed, and by the bottom right quadrant representing ISO and the bottom left quadrant representing aperture.

When all three settings are balanced, the shot will have what we call “the right exposure.” Along each side of the triangle, are measurements representing each of the elements and, by drawing a line between each setting, in theory, we can visualize the appropriate exposure using the exposure triangle.

Does Your Exposure Triangle Have to be Perfect?

NO and in fact, it’s NOT a perfect solution to exposure. If you visualize an exposure triangle and all of the possible combinations of aperture, shutter speed and ISO, you’ll quickly find that there are no guarantees for light exposure and that using the exposure triangle only provides a limited visual solution to understanding the relationship between ISO, aperture and shutter speed.

The exposure simply provides you with an understanding of how each component images the exposure of your footage. The purpose is to take control of exposure in your film and photos when you need to.

Increasing the exposure for one element of the triangle, such as the ISO light sensitivity, will require a decrease in one, or both, of the other elements in order to maintain exposure.

The camera often performs these tasks for you, but if you’re taking control in manual shooting mode, it’s important for you to have knowledge of this process in order to capture footage in the correct exposure.

Does your exposure triangle have to be perfect, though? Not at all! Changes in exposure can be used in a variety of purposes.

While perfecting the exposure triangle will help you to maximize your ability to capture great footage with perfect exposure, you certainly don’t have to have a perfect exposure triangle every time and there are instances when even perfecting the exposure triangle will not guarantee perfect exposure under certain elements or in unique situations.