Playing with Light: Understanding Aperture, Shutter Speed and ISO

Posted on October 19th, 2023

Welcome to another exciting blog post from Duncan MacBrayne Photography! 

Today, we're diving into a topic that's crucial for anyone looking to elevate their photography skills—understanding the basics of aperture, shutter speed, and ISO. 

These three elements form the Exposure Triangle, a fundamental concept that can make or break your photos. 

Whether you're a seasoned pro or a complete beginner, mastering these settings will give you greater creative control over your shots. 

We'll explain these terms in plain English, so you don't have to be a tech whiz to get the hang of it. 

Our aim is to help you capture photos that truly resonate, whether you're into portrait photography, landscape shots, or anything in between. 

So, if you've ever wondered how to get those warm, vibrant colours in your photos or how to freeze a moment in time perfectly, you're in the right place. 

Let's get started on this enlightening journey through the world of photography!

The Exposure Triangle: A Quick Overview

Before we dive into the nitty-gritty of each element, let's take a moment to understand the Exposure Triangle as a whole. Think of it as the magic formula that determines how your photos will turn out. It's the relationship between aperture, shutter speed, and ISO that dictates how much light hits your camera sensor, affecting everything from brightness and colour to motion blur and image noise. In simple terms, it's the backbone of good photography, especially when it comes to mastering photography lighting.

Why the Exposure Triangle Matters

Understanding the Exposure Triangle is like learning the ABCs before you start reading and writing. It's the foundation upon which all other photography techniques are built. Once you get the hang of it, you'll find it easier to adapt to different lighting conditions, capture true colours, and even add a creative twist to your shots.

The Three Pillars: Aperture, Shutter Speed, and ISO

These are the three settings that make up the Exposure Triangle. Each one plays a unique role in how your photo turns out. We'll be diving deep into each of these in the sections to come, so you'll know exactly how to use them to your advantage.

What is Aperture?

Aperture is essentially the size of the opening in your camera lens that allows light to enter. Think of it like the pupil of an eye: the larger the opening, the more light comes in. This is crucial for capturing well-lit photos, especially in different lighting conditions. Aperture is measured in f-stops, such as f/1.4, f/2.8, f/4, and so on. Here's where it gets a bit counterintuitive—the smaller the f-stop number, the larger the aperture, and vice versa.

The Role of Aperture in Depth of Field

One of the most creative aspects of using aperture is its impact on depth of field. A smaller f-stop number (which means a larger aperture) will give you a shallow depth of field. This is perfect for portrait photography where you want the subject to stand out against a blurred background.

Aperture and Colour

Aperture settings also play a role in capturing true colours and warm colours in your photography. A larger aperture allows more light, which can make colours appear more vibrant and true to life. This is especially useful when you're aiming for warm colours photography.

What is Shutter Speed?

Shutter speed is the amount of time the camera's shutter is open, allowing light to hit the sensor. It's measured in seconds or fractions of a second, like 1/200, 1/1000, or even several seconds for long-exposure shots. Shutter speed is your go-to setting for capturing motion in your photos.

Freezing or Blurring Motion

A fast shutter speed like 1/1000 will freeze fast-moving subjects, like a sprinting athlete or a flying bird. On the other hand, a slow shutter speed like 1/30 can create a sense of motion, turning flowing water into a silky blur or capturing the hustle and bustle of a busy street.

Shutter Speed and Light

It's essential to remember that shutter speed also affects the amount of light entering your camera. A fast shutter speed will let in less light, while a slow shutter speed will let in more. This is crucial when you're working in different lighting conditions and aiming to get vibrant colours in your photography.

What is ISO?

ISO is the setting that controls your camera's sensitivity to light. In the days of film photography, ISO was determined by the film you used, but in today's digital world, you can adjust it with just a few taps or clicks. ISO settings usually start at 100 and can go up into the thousands, depending on your camera's capabilities.

ISO and Digital Noise

Higher ISO settings allow you to shoot in lower light conditions without a flash, but there's a catch. Increasing the ISO also increases the amount of digital 'noise' or grain in your photos. So, while a high ISO can be a lifesaver in dim settings, it's essential to find the right balance to avoid compromising image quality.

ISO and Colour Vibrancy

Just like aperture and shutter speed, ISO also affects the colours in your photos. A lower ISO will generally produce more vibrant and true-to-life colours, ideal for capturing stunning portraits or landscapes.

Practical Tips and Tricks

Now that we've covered the basics of aperture, shutter speed, and ISO, let's talk about how to use these settings in harmony. The key is to balance these elements to achieve the desired effect, whether you're shooting a high-energy sports event or a serene landscape.

Balancing for Portrait Photography

For portrait photography, you might want a shallow depth of field to make your subject stand out. This means using a larger aperture (smaller f-stop number), a faster shutter speed to freeze the moment, and a lower ISO for vibrant colours. For more on this, check out our Portrait Photography service.

Adapting to Lighting Conditions

Different lighting conditions will require different settings. On a bright sunny day, you'll likely need a smaller aperture, faster shutter speed, and lower ISO. In contrast, a dimly lit room might require a larger aperture, slower shutter speed, and higher ISO.


We've journeyed through the fascinating world of photography, breaking down the Exposure Triangle into its core elements: aperture, shutter speed, and ISO. Understanding these settings is like having a magic wand that allows you to control light, capture motion, and bring out vibrant colours in your photos. It's not just about technical know-how; it's about using that knowledge to tell a story through your lens. Whether you're capturing the energy of a bustling city or the peaceful aura of a sunset, these settings are your tools to paint the scene as you see it.

If you've found this guide helpful and want to take your photography to the next level, don't hesitate to get in touch with us. We're always here to offer personalised advice or help you book a session. You can reach us at +447917717567 or drop us an email at [email protected].

Ready to put your newfound knowledge into practice? Why not book a session with Duncan MacBrayne Photography? 

We offer a range of services, including our highly recommended Portrait Photography service. Whether you're looking for a professional portrait, a family photo, or even a creative project, we've got you covered. Click here to Request an Estimate and let's create something beautiful together!

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