Hello, budding photographers! Ready to elevate your creativity, then let’s dive into the art of capturing light. And that starts with getting to grips with the exposure triangle and understanding aperture, shutter speed and ISO.
When we talk about exposure what do we mean? At its heart, exposure is about controlling the amount of light that reaches your camera’s sensor. When correctly managed, you’ll end up with superbly lit and exquisitely detailed images. So it is worth knowing!
Now, let’s unpack the exposure triangle – starting with basic definitions of each of its elements, before we go on the explore how each of them affects the others. And how their optimal balance is crucial for creating those stunning images I am sure you want to create.
Aperture
First up is aperture. Imagine aperture as the eye of your camera. Like an eye it dilates or contracts, controlling the light that enters. F-stops denote the size of the aperture, with lower numbers signifying larger openings, and higher ones indicating smaller ones.
As you would expect a larger opening lets in more light than a smaller opening. Therefore, under similar lighting, a lower f-stop (e.g., f/1.8) allows in more light than a higher f-stop (e.g., f/16), producing a brighter image. A higher f-stop, on the other hand, results in a darker image as less light is being let in.
If too much light is let in, the image will become what’s known as over-exposed and if not enough light is let in the image becomes what’s known as under-exposed.
Aside from affecting image brightness, aperture size also has a direct impact on the depth of field. As an example, a larger aperture (i.e., lower f-stop) narrows your depth of field. This means that only a small part of your image will be clear, while the rest is blurry—ideal for portrait photography where a crisp clear subject stands out from a blurry background.
Alternatively, a smaller aperture (higher f-stop) gives you a wider depth of field, ensuring a larger portion of the scene is in focus. This attribute works great for landscape photography, providing crispness to your broad scenic shots.
Shutter Speed
Next up is shutter speed. This term defines the duration your camera shutter is open to expose the sensor to light. Faster shutter speeds, like 1/1000 means the shutter is open for 1/1000th of a second whilst 1/2 means the shutter is open for 1/2 second.
In addition to the aperture the shutter speed can also be used to control the amount of light that hits the sensor. The longer it is open the more light enters and hits the sensor.
Similar to the aperture shutter speed also has another atrribute apart from controlling light. In this case ti is the ability to freeze motion or create blur. Using a high shutter speed would result in freezing the motion which is ideal for actions shots like sports and nature where you want a clear sharp image without any blur. For instance you would be able to take a clear crisp image of a hummingbird in flight.
On the other hand using a slow shutter speed would create an image with blur because the sensor is exposed for longer and would therefore capture all the action whilst exposed. I am sure you have seen night shots of car light producing streaks of lights.
ISO
Our final corner of the exposure triangle is the ISO. Unlike the first two elements which control the exposure of the image by controlling the amount light that hits the sensor, the ISO controls the exposure by increasing or decreasing the sensor’s sensivity to the incoming light.
When the ISO is increased, the sensor becomes more sensitive to light, enabling photographers to capture brighter images in low-light situations. Conversely, decreasing the ISO reduces the sensor’s sensitivity, making it ideal for well-lit environments or when photographers desire to capture images with less noise. The ability to manipulate the ISO allows photographers to have more control over the exposure of their photos and adapt to various lighting conditions.
But be cautious though, higher ISO settings can lead to grainier images or noise, which can impact your image quality. Having said that many photographer deliberately used higher ISO settings because grainier images are part of the image they are trying to create.
Putting It All Together
That covers the basic definitions so now it is time to explore where the real magic lies – and that is how each element of the exposure triangle interact with each other.
We mentioned earlier the depth of field that you can change by altering the aperture. If we were alter the size of the aperture then the amount of light entering the camera would change. We therefore need to compensate for this change be altering the settings on either the shutter speed or ISO.
So for example if we wanted a shallower depth of field we would use a wider aperture which would increase the amount of light entering the camera. To compensate we can either have a faster shutter speed or lower the ISO to avoid the image becoming over-exposed.
Another example would be if you wanted to shoot a flowing waterfall and capture a smooth blur effect. To achieve this effect, you would need to set your camera to a slow shutter speed. However, this would allow too much light onto your sensor with the probable result of an over-expose image. In this case you can either choose a smaller aperture or select a lower ISO level.
When deciding which of the elements to alter you would need to take into consideration the effect of changing it would have on the image. Remember each of these elements in addition to controlling the exposure also have a secondary effect. For instance, compensating for a slow shutter speed in order to capture the smooth blur effect of the flowing waterfall by reducing the size of the aperture would also change the depth of field.
At the end of the day it’s all an exposure balancing act using the three element in different configurations to get the desired resullt. The only way to get comfortable with it is by practicing it with your camera. So, let’s get started with some simple projects that will help you understand the interplay of the exposure triangle.
Aperture Exercise
First, set up an object in a place with consistent lighting. Let’s stick to the setting of aperture for our initial exercise. Begin shooting with different apertures whilst keeping the shutter speed and ISO setting the same. Note how the size of the aperture affects your image’s brightness and depth of field.Aperture
Shutter Speed Exercise
Your second exercise involves shutter speed. Try snapping images of the same subject but at different shutter speeds. Keep your ISO and aperture constant. You’ll notice how changing your shutter speed impacts motion capture in your images.
ISO Exercise
After you’ve mastered shutter speed and aperture, it’s time to tinker with ISO levels. Experiment with different ISO settings in various lighting conditions. Pay attention to how it affects the brightness and crispness of your images.
Some Final Thoughtd
During your practice, remember: there’s no universally “correct” exposure, so don’t get hung up on the “perfect” settings. It’s about getting the balance that’s right for your particular scene and desired effect. So if something doesn’t work the way you intended, consider it a learning experience.
Understanding aperture, shutter speed, and ISO is merely a starting point, a guide. Once you understand the simple principles of the exposure triangle, and have become comfortable with adjusting your camera settings to adapt to the different photographic senarios, don’t be afraid to break the rules. Photography is just as much an art as it is technical. So indulge your creativity!