Outdoor nature scenes rarely let you control the light, so the controls that matter are the three on your camera. Aperture, shutter speed, and ISO together set the exposure, and each one also changes the look of the photograph. Understanding the trade-offs is more useful than memorizing fixed numbers.
The exposure triangle
Exposure is the total amount of light recorded by the sensor. Three settings control it, and moving one usually means compensating with another:
| Setting | Controls light by | Also affects |
|---|---|---|
| Aperture (f-number) | Size of the lens opening | Depth of field |
| Shutter speed | How long the sensor is exposed | Motion blur / sharpness |
| ISO | Sensor sensitivity (amplification) | Visible noise |
Aperture and depth of field
A smaller opening (larger f-number such as f/11 or f/16) keeps more of the scene in focus, which suits wide landscapes where you want both a foreground rock and a distant peak sharp. A wider opening (smaller f-number such as f/2.8 or f/4) isolates a subject against a soft background, useful for a single wildflower or an animal.
Very small apertures can soften the image through diffraction, so many landscape photographers stay around f/8 to f/13 when they want broad sharpness without that penalty.
Shutter speed and motion
Shutter speed decides whether movement is frozen or blurred. A fast speed such as 1/1000 s freezes a bird in flight; a slow speed such as 1/4 s or longer renders a waterfall as smooth, continuous motion. Slow speeds require stabilizing the camera, usually on a tripod.
These are starting points to adjust from, not rules. The correct exposure depends on the light in front of you.
ISO and noise
Raising ISO lets you keep a usable shutter speed when light is low, at the cost of more visible noise. Modern cameras handle moderate ISO values well, so it is generally better to raise ISO and keep a sharp frame than to accept blur from too slow a shutter speed.
A simple field workflow
Working through the settings in a consistent order keeps decisions fast in changing light:
- Decide what the photo is about, and how much depth of field it needs. Set aperture first.
- Choose a shutter speed for the motion you want, fast to freeze or slow to blur.
- Raise ISO only as much as needed to keep that shutter speed at a correct exposure.
- Check the histogram, not just the screen brightness, to confirm highlights are not clipped.
In bright snow or on water, the camera's meter often underexposes because it assumes an average grey scene. Adding positive exposure compensation keeps snow looking white rather than dull grey — a frequent situation when photographing Canadian winters and alpine lakes.
Continue reading
Once exposure is reliable, the next decision is framing. See Composition Techniques for Outdoor Scenes, then read how light changes through the year in Working with Natural Light Across Canadian Seasons.