Fully-fledged DSLRs have a couple of settings that you will need to adjust based on the lighting conditions and your ideal outcome. Known as the exposure triangle, having a proper understanding of ISO, Shutter speed and Aperture is necessary for any photographer who wants to take amazing photos.
We’ll go through what each of these terms means and how you can adjust each setting independently and simultaneously to get the best results in different lighting conditions. Let’s get started by explaining the meaning of each setting:
Aperture is the opening in the lens through which light passes to reach the camera. It is represented in terms of an f-number or f-stop, where the smaller the number, the wider the Aperture. For instance, a lens with a maximum aperture of f/1.8 will let more light through than one with f/2.2. So, the f/1.8 lens will be a better choice for shooting in darker scenarios, where you need as much light as possible.
Shutter Speed controls how long the shutter is open for, therefore affecting the amount of light the sensor is exposed to. Shutter speed is measured in terms of a fraction of a second, you’ll see it in your camera settings as an adjustable figure, e.g., 1/4000 or 1/4000th of a second. The more the time, the more the light and details the sensor can gather. That is why slow shutter speeds are usually preferred while taking photos in low light.
ISO can be defined as digital gain on the camera sensor. It is a way to increase the brightness of a photo if you cannot use a wider aperture or slower shutter speed. In photography, ISO is measured in numbers whereby the lower number represents a darker image, and the higher one represents a brighter image. However, as ISO is digital and not optical, increasing the ISO number is not necessarily a good thing because it leads to more noise in the photo. In most scenarios, you will want to keep the ISO as low as possible for a noise-free image.
Finding the right balance
Each of the primary settings mentioned above work together to balance the light you get in your final image. So, you’ll need to find the right balance between the Aperture, shutter speed, and ISO. The primary factor that affects the adjustments of these settings is usually the amount of light your subject is exposed to.
How to balance settings in light or dark scenarios
When your subject is exposed to low light, you will need a wider aperture and slow shutter speeds to allow as much light into the sensor as possible. In this situation, you may also need to increase your ISO settings to brighten up the image. A great example of how you can get amazing results in dark conditions is outlined in our guide on long-exposure photography – check it out to see exactly how to set your camera up to achieve awesome night-time shots.
However, if your subject is in a bright environment, you may have to increase the aperture to decrease the amount of light coming through the lens and decrease the shutter speed to decrease the amount of time the shutter is open. Both adjustments will ensure your image isn’t overexposed while allowing you to take your shots instantly.
Download the free Camera Settings Flashcard
If you’re more of a visual learner, you can download this handy flashcard that will show you how Aperture, Exposure and ISO are adjusted for light and dark lighting conditions. To gain access to it, simply subscribe to our Luks Magazine Newsletter. As an exclusive member, you’ll also gain access to subscribers-only content from our team and the community.
That sums it up for this brief explanation of Aperture, Exposure and ISO. As with all skills, it takes practice to grow, so get out there and try your hand at full manual mode in the daytime and at night.