In the words of George Eastman, “Light makes photography. Embrace light. Admire it. Love it. But above all, know light. Know it for all you are worth, and you will know the key to photography.”
In this post we’re going to introduce the exposure triangle, and show you how three separate technical settings come together to form one exposure. Once you understand how our cameras control light, you’ll be able to customize your settings to take incredible landscape photos.
The Three Sides To The Triangle
The triangle is essentially the result of how three settings combine to create an exposure: it controls how much light enters (Aperture), how long it can enter (Shutter Speed), and how sensitive the camera is to the light (ISO). All three aspects are measured in stops of light, or fractions of stops, but we’ll go further into that another time. Whenever you adjust one it will change your exposure, and so knowing how each affects the look of your photograph is very important in choosing how you make adjustments.
The aperture on your lens plays two major roles:
- It determines how much light enters the camera.
- It controls, in part, the Depth of Field (DOF) of your photo (DOF is also affected by the focal length of your lens and the distance from your subject in focus).
Depth of Field
When shooting landscape photos, you typically want as much of the scene to be in focus as possible. To achieve this, it’s best to select a narrower aperture like F/8 -F/11. While many people believe the smaller the aperture, the greater the depth of field, it’s been proven that every lens has an optimal sharpness and if you close off your aperture all the way the photo may be less crisp than it would be at the optimal aperture. For most lenses this range exists between F/7.1 and F/16.
→ Related reading: 11 Steps to Tack-Sharp Landscape Photos
Since smaller apertures allow less light to enter the camera, often times while shooting a landscape photo you’re either going to need a tripod to compensate for the longer shutter speed, or you’ll need to increase your ISO.
The shutter speed built into your camera body plays two major roles as well:
- It dictates how long light is recorded by your sensor
- It determines the motion of your subject
Keeping the shutter open for longer, known as a long exposure, will add motion blur to moving objects depending on how fast they’re moving. Using a narrow aperture, low ISO, and/or a neutral density filter will help you to achieve this effect.
Longer shutter speeds increase the amount of time light is able to hit your camera’s sensor. If your meter reading is telling you your shutter speed is going to be 1/60th of a second, you should use a tripod, or begin to increase your ISO.
ISO is typically the last setting you’ll adjust as it really only helps to increase your Exposure Value (EV). Camera bodies that can handle high ISO are excellent because they allow you to capture dynamic shots of the milky way without leaving much noise in the photograph.
ISO is also there in situations where you need to use a narrow aperture, requiring a longer shutter speed, but you also don’t have a tripod to stabilize the camera.
Finding A Balance
Creating the perfect exposure is a triangle because all three aspects will always be a factor. How you increase/decrease one will require you to compensate one of the other two settings. The best way to understand this fragile balance is to shoot in manual and examine how your meter changes as you adjust each setting.