Beginner Guide – Basic understanding of ISO, Shutter Speed and Aperture

Beginner Guide - Basic understanding of ISO, Shutter Speed and Aperture

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Beginner Guide – Basic understanding of ISO, Shutter Speed and Aperture

I have got this plan in my mind a few times to discuss some of the basics of Photography and its elements (ISO, Shutter Speed, and Aperture) thoroughly. Still, most of the time, when people are just getting started with Photography, and they ask me some of the basic questions, most of the content I found online is limited mainly to Digital Photography. Still, many times finding myself ending with the conclusion that someone else would’ve put quality content regarding basic Photography and some of the photography elements such as IOS, Aperture, Shutter speed and would’ve done it in a better way. That’s why I’ve written this photography guide for you to learn basic Photography via analog devices. 

If you are into photography, you must have heard the term ‘Exposure triangle.’ If not, then this article is a must-read to photography and sharpen your skills.

This triangle has three components; each one is explained below, along with the tips to use in your photography. Just read on!

The Exposure Triangle

The Exposure Triangle consists of aperture, shutter speed, and ISO. These three camera and lens components work in harmony to regulate the amount of light that strikes the light-sensitive surface (shutter speed and aperture) and the sensitivity of the surface (ISO). Along with setting the best lighting conditions for a photograph, each of these components has its own side effects or drawbacks. So every function should be used in a good balance to get perfect results. The Aperture or iris controls the depth of field and brightness, shutter speed can blur or freeze motion, and ISO can add or subtract film grain to the image. Let us now consider all three of these functions individually.

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What is ISO?

Before we understand the relationship between ISO, shutter speed and aperture, it’s important to figure out the role of each one of these features. ISO is an acronym, but no one really knows what it stands for. What we do know is that the ISO system was established in the 70s and it focuses on the film speed. This is a combination of DIN and ASA, which were the systems used before it.

What the ISO numbers do is they show the sensitivity of film to light. Basically, if the ISO number is low, then the film has a slow reaction to light. However, if the ISO value is higher, then the film reacts to light faster. Higher ISO films are useful in the lower light situations. However, slower films are better if you have a bright light photography situation.

Some of the more common film speeds are things like 3200, 1600, 800, 400, 200 and 100. As you can see, the numbers are halving here, and the higher the ISO, the faster the reaction time. So an 800 ISO reacts half as fast when compared to 1600 ISO. That’s why it’s important to assess what you need and based on that you can identify the right option. It’s a good idea to keep in mind, and it will convey a very good set of benefits.

ISO is actually numbers that signify the sensitivity of film to light. The films with higher ISO are faster and used in darker scenarios, while lower ISO films are slower and are used in brighter situations.

The higher the ISO value, the brighter the photograph. So, for example, ISO 3200 will produce a much brighter picture than ISO 200. But this brightness comes with the drawback of making the picture noisy or grainy. Similarly, a picture with a lower ISO will be darker but less noisy.

In digital cameras, you can change the ISO at any time, but otherwise, ISO is fixed by the film you have chosen to load in the camera and can only be changed by changing the film or choosing a different “exposure index.” Therefore, it is important to load a film that suits the lighting you are going to be shooting in.

For example, an 100 ISO film is better suitable for brighter daytime shooting.

3200 ISO film is most sensitive to light and is suitable for low-light shooting.

Generally, the higher ISO makes the photograph more grainy, but how grainy the photograph also becomes greatly depends on how the photograph was developed and what chemicals were used.

Shutter speed

Every camera has a shutter, whose purpose is to allow or stop the light to travel through and reach the film. If you close this, then it prevents the light from hitting the film. Shutter speed basically covers the amount of time that a shutter is open. Slow shutter speeds allow light to go through for a long period of time, whereas the fast shutter speed doesn’t allow you a lot of time for the light to go through.

Normally, the shutter speed is measured in fractions of seconds or seconds. Shutter speeds are usually from 1 to 1000. There’s also a doubling and halving system, and you can usually change how quick light will travel to the film. Normally you have different stops for the shutter speed, and when you increase with a stop, you are basically halving the amount of time your light travels to the film. Decreasing the shutter speed doubles that time.

What this means is that whenever you have a faster shutter speed, even if the subject is moving, the fast shutter speed will freeze everything into place. If you go for a lower shutter speed, you will notice motion blur whenever you have movement in your picture. The same thing can be said if the camera doesn’t have enough support.


An aperture is a small hole inside all lenses of cameras. This tiny hole is formed by metallic leaves that surround this hole. This is also sometimes called iris (just like the iris in our eyes). The aperture allows light to pass through it. The bigger the aperture, the light it lets through, and the brighter is the image formed.

It is measured as a fraction of the focal length of the camera lens, so small numbers actually relate to a larger aperture. Contrarily, larger numbers relate to smaller apertures. For example, if an aperture measures f2.8 and the other f22, a 2.8 aperture lets much more light pass through while 22 aperture will let less light pass through the aperture. These are called f-numbers.

“Opening up” and “stopping down” are the terms used when the aperture settings are changed. When you “open up” the aperture by one stop, e.g., moving f/8 to f/5.6, you double the amount of light that travels through to the film. When you “stop down” the aperture or go from f/2.4 to f/4, the amount of light becomes half.

This is not it; the aperture also defines the depth of field. The depth of field decides the sharpness and blurriness of the picture. Shallow depth of field is used when you want to capture a person and blur the picture. It is best done with a larger aperture. In contrast, if you want to take a picture of beautiful scenery, you want the entire picture to be sharp. For this, a smaller aperture is used to achieve a broader depth of field.

Why is it important to understand this?

This provides an amazing amount of customisation options for photographers who understand these things. In the beginning, you may use a lot of film and time experimenting with different settings to see which style you like the best. Just like a painter with brushes and a canvas, you will develop specific practices and preferences of your own when you produce your artwork.

Once you understand these three basic tools of analog photography, you have the power to create more artistic and professional shots than ever before. ISO, shutter speed, and aperture all work together in various ways to deliver unique results. Do not limit your experimentation as you try out all the different settings on your new camera. You will quickly find that they give so many more options than you could possibly find even on the most advanced smartphone. Your new photography hobby or career begins with the basics but can grow ever more exciting as you learn.

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