Each of the three aspects of the triangle relate to light and how it enters and interacts with the camera.
The three elements are:
- ISO – the measure of a digital camera sensor’s sensitivity to light
- Aperture – the size of the opening in the lens when a picture is taken
- Shutter Speed – the amount of time that the shutter is open
Exposure is the control of light reaching the image sensor via the combination of aperture and shutter speed. The sensor's sensitivity to light can also be adjusted via the ISO setting for additional control over how bright the recorded image is.
The ISO (international Standards Organization) determines the sensitivity of the sensor in your camera, which in turn affects the exposure of your photos.
The ISO scale typically starts at 100, and continues to double from this point to the boundary of your camera’s capabilities: 100, 200, 400, 800, 1600… The starting and ending points of this range and how well the camera handles the ISO depends solely on the camera that you’re using.
Low ISO (50-400)
- Bright light
- Shooting on a tripod
- Making large prints
High ISO (500-3200)
Aperture is measured using something called the f-stop scale. On your camera, you’ll see ‘f/’ followed by a number. The number denotes how wide the aperture is, which in turn affects the exposure and depth of field (also tackled below); the lower the number, the wider the aperture.
Larger aperture, faster shutter speed; smaller aperture, slower shutter speed. Increase aperture by one stop and decrease shutter speed by one stop = equivalent exposure (and vice versa).
Understanding Shutter Speed
Shutter speed, also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, it can help to freeze action completely. If the shutter speed is slow, it can create an effect called “motion blur”.
Slower shutter speeds will result in blurred motion, which can be useful for creative shots. Fast shutter speeds, on the other hand, will freeze motion. With practice, you will get to know instantly which shutter speeds are required for every occasion that presents itself.
For the shots where you have a little more time to prepare, a good knowledge of how to use slow or fast shutter speeds to your advantage will add an infinite number of images or ideas for your portfolio or stock library.
Minerva Layout Horizontal
By Kyle Coberly