Understanding ISO and its Importance in Photography

When you’re starting to learn about photography and take the leap into that world, there are a lot of different things you can learn about.

You can argue about what you need to learn first.

Eventually, you’re going to get around to this thing called ISO.

If you’re truly a beginner with photography, you aren’t going to know what ISO is yet.

Although everything with photography is important, ISO is arguably one of the most important.

Once you’re fully understanding ISO, you’ll notice how much better your photography skills are. Understanding this aspect of your camera will put you on a path to becoming a much better photographer.

Understanding ISO Photography

ISO is a part of the triangle in photography that can be considered one of its pillars. The other two are shutter speed and aperture.

Changing your ISO can greatly change the way your image looks.

How does ISO affect your images?

What is ISO?

What is the best way for you to utilize ISO?

Just knowing how ISO works with every picture you want to take, will put you above most amateur photographers.

Your skills will go from mediocre to at least average.

A vast majority of photography is understanding your camera. Understanding your camera means setting up everything for your shot will be easier.

You’ll be able to get the shots you want much easier than the average photographer.

What is ISO?

understanding ISO

The easiest way to explain ISO is to say that it’s a camera setting that you can adjust that will either make your image look brighter or darker.

Don’t get this confused with the lighting of your photo. Lighting in photography is going to be completely separate from your ISO.

The higher your ISO number, the brighter your image will appear.

ISO is great because it allows you to adapt to the environment you’re in. Say you’re in a darker environment and want to try and capture more details, you can raise your ISO and the picture will brighten up.

The drawback of this is that you may experience what is called digital noise. This is when you see specks and little white dots around your image. You’ll look at an image and see that it’s a bit grainy.

Yes, this could be from a filter, but when it’s not, you can thank digital noise for that look. It’s typically not what you want when you’re looking to display fine details in your images.

And for the most part, this has nothing to do with the lens that you choose to use. Whether it’s a Canon RF 50mm or a Canon 16-35mm lens, digital noise can easily happen when the conditions suit that to happen.

However, this should be a last resort. Only raise your ISO when you can’t brighten your image with your shutter speed or aperture.

ISO will almost always be the last thing you touch.

It’s easy to think of ISO as a last resort. It’s only going to help you try to enhance your image when the environment isn’t cooperating the way you want it to.

ISO Values

Your camera ISO is going to have different values.

This is typically something that you can adjust fairly easily before you take a photo.

With ISO, you’re mostly going to have a general range that you can adjust your values too. There are ways you can manually set your ISO to a specific number, depending on the camera you have.

The general ISO values are as follows:

  • ISO 100
  • ISO 200
  • ISO 400
  • ISO 800
  • ISO 1600
  • ISO 3200
  • ISO 6400

Notice how each number doubles. With ISO values, going from ISO 100, which is considered to be a low ISO, to ISO 200 means that you’re doubling the brightness of your image.

This is the same between ISO 200 and ISO 400 and so on.

Shutter speed – 1/250, Aperture – f5.6, ISO – 100
Shutter speed – 1/250, Aperture – f5.6, ISO – 200
Shutter speed – 1/250, Aperture – f5.6, ISO – 400
Shutter speed – 1/250, Aperture – f5.6, ISO – 800
Shutter speed – 1/250, Aperture – f5.6, ISO – 1600
Shutter speed – 1/250, Aperture – f5.6, ISO – 3200
Shutter speed – 1/250, Aperture – f5.6, ISO – 6400

When you take a photo with ISO 200 then take the same photo at ISO 400, you’ll notice a significant difference between the brightness of the image.

This is why it’s not highly recommended that you never go to ISO 6400. That is only for extreme cases.

Typically you won’t be able to see much of an image when your ISO is that high. You’ll get a lot of white.

Using ISO

Because your environment is always changing around you when you’re a photographer, you need to know when you should change your ISO.

There are going to be situations that call for you to always use a lower ISO and some situations that will require a higher ISO.

Shutter speed – 1/250, Aperture – f5.6, ISO – 100
Shutter speed – 1/250, Aperture – f5.6, ISO – 200
Shutter speed – 1/250, Aperture – f5.6, ISO – 400
Shutter speed – 1/250, Aperture – f5.6, ISO – 800
Shutter speed – 1/250, Aperture – f5.6, ISO – 1600
Shutter speed – 1/250, Aperture – f5.6, ISO – 3200

Again, you should really only look at adjusting your ISO manually when you can’t get the look you want after adjusting your shutter speed and aperture.

Using Low ISO

When shooting any type of photography, you should really try to stick to the lowest ISO possible.

A majority of cameras are going to stay around ISO 100 or 200 depending on what type you have.

I use the Canon EOS-R and the ISO is always hanging around 100.

If you’re shooting outside during the day, you really don’t have a reason to actually raise your ISO.

Most of the time when you’re on an automatic mode, where your ISO is set by the camera, it’s going to be a low ISO. This is because your camera is pretty good at adjusting for the light.

It will see that you already have plenty of light so there’s no need to try and brighten up your actual image.

If you’re in a darker area, you still don’t necessarily have to mess with your ISO. When you have a camera that’s possibly on a tripod or isn’t going to move much at all, simply changing your shutter speed is going to allow more light to get into the camera.

More light in the camera means a brighter image.

You need to be careful with a slower shutter speed. It’s very easy to have motion blur when your shutter speed is slower.

So, if you’re going to have any type of camera shake, it might be a better idea to change your ISO while having a faster shutter speed.

You could also bring your own light sources when you’re in a dark environment. If you need a smaller, yet powerful light to use, the Aputure Amaran light is a great option. This could make it so you won’t have to touch your ISO at all.

Using High ISO

Having a low ISO is always ideal, but you’re going to run across instances when you’ll need a higher ISO.

As mentioned above, if you’re fighting against motion blur, a higher ISO is going to be required.

For example, say you’re at the lake and a jet ski is going past you, you’ll probably want to eliminate as much motion blur as possible.

To do this, you’re going to have to keep a fast shutter speed but raise your ISO.

Raising your ISO will allow you to have enough light in your camera while your camera is taking the picture. Your image will be clear and crisp without any motion blur.

At the same time, it’s going to be bright enough so you don’t have to worry about missing out on details.

If you’re going to be holding your camera all the time instead of using something like a tripod, you might want to consider using a high ISO depending on what you’re shooting.

Pictures that could possibly have a lot of movement will require a high ISO combined with a fast shutter speed.

Again, most cameras are going to be able to set your ISO automatically, but at the same time, nothing is perfect. To be safe, always take a few test shots to determine if you need to make any adjustments.

Get High Image Quality

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Shutter speed – 1/250, Aperture – f5.6, ISO – 1600
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Shutter speed – 1/250, Aperture – f5.6, ISO – 400
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A majority of the time, if you already have enough light, you aren’t going to have to mess with your ISO at all. Cameras typically do a good job at giving you the best recommended ISO.

However, during the times you do have to mess with your ISO, you want to make sure you get the highest quality image possible.

You’ll recognize if you have enough light to get the shot you want.

When you don’t have enough light, ISO should be something you consider changing.

To get yourself set up for the best possible shot, that will have as little digital noise and motion blur as possible, you need to essentially sync your aperture, shutter speed, and ISO.

Setting your aperture should be the first things you. This will give you the depth of field that you want so you know exactly what should be in focus.

Your ISO and shutter speed are things that you’re going to have to tweak. Work with shutter speed first.

Once you feel like you’ve got the right shutter speed, by doing a few test shots, you can then move on to ISO.

Start at the lowest then start increasing the ISO until you get the desired brightness in your image.

Know Your ISO

You will very rarely go into a photo shoot, whether it be inside, outside, or elsewhere, knowing exactly what your ISO should be.

You could go into it knowing a range at which it should be set, but until you have everything set on your camera, you won’t know for sure.

Digital cameras are stepping up with what they provide the user. You can very easily never have to touch ISO and let your camera set it automatically.

Remember that the camera, although most of the time, will give you a good ISO, isn’t perfect. Knowing how to adjust your ISO properly is going to set you apart from other photographers and you’ll be more ready to shoot in any kind of environment.