What Does ISO Stand for in Photography?

Photography is a phenomenal art form and a truly rewarding hobby to pick up. One aspect of taking photos that can put people off, however, is the number of confusing terms they have to deal with. What does ISO stand for in photography anyway? In this article, we’re going to find out.

While the automatic settings of your camera can do a lot of the “thinking” for you when you’re first starting out, you don’t have to be a budding photographer for long before you start experimenting with your manual settings.

Getting to grips with manual mode is a critical part of becoming a better photographer. Your ISO setting is no exception. On this page, we’ll explore what ISO stands for, what it’s used for in photography, and how to use it in different environments.

Read on to learn more.

ISO — Photography Definition

If we’re being technical, ISO stands for the International Organization for Standardization. In short, this is an internationally recognized body that sets standards for all manner of electronic devices, features, and technologies.

One such standard set by this organization is photography film’s sensitivity to light. Back before the days of digital cameras, the ISO of film referred to its ability to “gather” light. The higher the ISO number, the more light it was able to absorb effectively.

ISO in Digital Cameras Explained

Today, ISO refers to how sensitive a camera’s sensor is to light. For this reason, changing the ISO setting on your camera will affect how it performs in different lighting conditions. The higher you set your ISO, the more your device will react to light.

In darker environments, therefore, a higher setting is usually required. It’s worth keeping in mind that ISO is just one factor to consider when adapting to your available light. We explore the other things to keep in mind further down this page.

ISO Range in Cameras

As a general rule, the ISO range that a camera offers tells you a lot about how well it will perform in different lighting conditions. A smaller range is more typical of cheaper models, while pro-grade cameras come with a much broader spectrum.

An average range is somewhere around 200-1600, but more expensive cameras can go significantly higher than this.

ISO, Exposure, and the Exposure Triangle

As mentioned earlier, ISO isn’t the only thing you’ll have to think about when it comes to getting the right exposure for your images. You’ll also have to factor in aperture and shutter speed to the equation.

These three elements, ISO, aperture, and shutter speed, are what’s referred to as the exposure triangle in photography. It’s a fundamental aspect of improving your skills as a photographer.

Aperture Explained

In a nutshell, the aperture of your camera refers to the size of the physical opening that lets light into the lens. This setting can be tweaked to let more or less light into your setup depending on what you’re shooting and how much light you have available.

Shutter Speed

Shutter speed refers to how long it takes for the shutter of your camera to close when taking an image. A slower speed lets in more light, while a faster speed can let in significantly less.

Tweaking this setting is another way to affect how much light gets into your camera.

Priority Modes

Most modern cameras come with two “priority” modes:

  • Aperture priority
  • Shutter priority

If you’re new to changing the manual settings of your camera, these modes can be a great way to get started without “messing up” your images.

Aperture priority lets users set a specific aperture value manually while letting the camera choose an appropriate shutter speed automatically. Shutter priority is exactly the same concept in reverse — a shutter speed can be set manually, with the camera handling aperture.

We recommend experimenting with these settings – they’re a great way to learn more about what gets results when taking photos.

How to Use Your ISO Setting

If you’re wondering how to make the most out of your ISO setting, we outline some basic tips below.

The Automatic Option

If you’re brand new to photography, or just want to make sure that things don’t get “messed up,” most modern cameras come with good enough automatic settings to do the thinking for you.

In a casual photography setting, there’s no shame in relying on automatic settings. Once you’re taking shots in low-light environments, however, manual settings are probably the way to go.

The level of control that comes with manual mode is hard to argue with.

When to Use High ISO

As a general rule, low-light environments call for a higher ISO setting. Increasing your camera’s sensitivity to light will allow it to “amplify” the appearance of the scene you’re capturing and produce an image that looks brighter overall.

It’s important to keep in mind that ISO has a close relationship with image noise. The higher your ISO setting, the more likely it is that your image will have noise distortions and grains. This means camera shake is extra deadly when using a higher ISO.

For this reason, only raise your ISO if you don’t have the light you need.

We outline some more use cases for a high ISO setting below.

When Capturing a Moving Subject

While it’s true that image noise is often an issue with a higher ISO, increasing the setting can still prove useful when capturing a moving subject.

The higher shutter speed you’ll need to use when capturing movement can result in a very dark exposure. Unless you raise your ISO that is.

When You’re Indoors

The darker environments that are often encountered indoors can call for a higher ISO. It’s best not to go crazy, but bumping the setting a little can work wonders for many of your shots. Experiment with your levels to find what works for you.

When to Use Low ISO

In brighter scenes, a lower ISO setting can often work well. As a general rule, it’s a good idea to take advantage of whatever light you have available before resorting to raising your ISO. If you have plenty of light in your scene, keep your settings down to an appropriate level.

Check out some other examples below.

Landscape Nature Photography

Another application that’s common for lower ISO is with landscape nature photography. Image noise can ruin any kind of photo, but it’s especially noticeable with this kind of photo. The longer exposures used for landscapes mean that image noise can ruin your final result.

Keeping your ISO setting nice and low can significantly reduce the risk of image noise.

When in Doubt…

It’s a bit of an oversimplification, but a lower ISO setting tends to be the safest bet. If you’re unsure which level to choose, either opt for automatic settings or choose a number that’s relatively low.

Higher ISOs can be tricky to deal with, especially if you’re free-holding your camera and don’t have a tripod available.

a bright image like this requires very low iso
A bright image like this uses a very low ISO setting


Learn about macro photography here

Can you change ISO in RAW?

ISO — Conclusion

While photography terminology can be intimidating to the uninitiated, most of this stuff is much simpler than you might expect. The main thing to remember with ISO is that it describes how sensitive your digital camera is to light.

The higher the ISO, the higher the sensitivity. Just remember that shutter speed and aperture are just as important when it comes to image exposure.

Happy shooting!

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