Understanding Exposure: The Exposure Triangle
The exposure triangle consists of three main elements that affect the exposure in a photograph: aperture, shutter speed, and ISO. In order to capture a perfectly exposed image, all three elements must be in balance.
These three things that need to happen:
- The shutter needs to open long enough so that light from whatever scene we want to record hits the front element.
- Light must hit the backside of the film/sensor at just the right time.
- We must expose the film/sensor with enough light to create a latent image which can later be developed into something visible.
If any one of these steps fails, no matter how small, we won’t’ get anything useful out of our images. Let’s take a look at each step individually.
Exposure Triangle: The Three Basic Elements
The first thing you need to understand when talking about controlling exposure in photography is that there are three main factors involved: aperture, shutter speed, and ISO. These terms may seem like they mean different things but really they just refer to one factor at a time.
Photographers Resource Center is supported by readers. Product links on Photographers Resource Center are referral links. Read more here.
Shutter Speed – How long you leave the shutter open while taking photos. Shorter exposures allow more time for light to enter the lens and reach the sensor. Longer exposures mean less light reaches the sensor. This is why when shooting in low-light situations, people often use longer shutter speeds than they would normally do.
Aperture Size – A smaller opening allows more light into the lens. Larger openings block out more light. When using larger apertures, photographers can increase the depth of field which means objects closer to the camera appear sharper than those farther away from the camera. Smaller apertures also make images brighter because there is less distance between the subject and the background.
ISO – The last variable is the ISO setting. This controls how sensitive your camera’s sensors are to light. When you raise the ISO setting, you allow less light into the camera but also amplify the image data coming back from the sensor. So what does all this mean? It depends on whether you want a brighter picture or a darker picture. Let me explain…
Putting It All Together
To get accurate exposure, we need to balance the three variables of the exposure triangle by adjusting our settings accordingly. In order to achieve proper exposure, it takes practice and experimentation with different combinations of aperture size, shutter speed, and ISO.
But once you master that process, you’ll have mastered photography!
Are you up to a weekly challenge? Check out our challenges HERE.
Need photography tips? You can find them here.
Subscribe to join our photo community and receive updated articles, tips, and special offers from our sponsors.
Connect with us on social media.