ISO Explained. Understand your camera settings:

What is ISO and how to use it!

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Camera settings

History of ISO

ISO came from film cameras and was used for the same purpose: describing the sensibility of a film to the light. Today digital cameras don’t need film and use a sensor. This sensor can be more or less sensitive to the light, exactly like film was; For this reason, the term is still in use.

Notes: Back in time, you needed to change the film to change the ISO, today, fortunately, you only need to change your camera setting.

What is ISO?

If you’re into photography, then there is no doubt you have heard/seen this term before while speaking with other photographer or just on your camera settings.Your camera’s ISO setting is one of the three key components when it comes to achieving proper exposure and overall photo quality. ISO is merely your camera’s internal brightness and controls how sensitive the camera sensor is to the light.

The higher the number, the higher the sensitivity and the brighter the image. For instance, ISO is handy when you are shooting in a dark environment and need a little bit of extra brightness for your photo.

With that said, raising the ISO too high comes with consequences; Indeed, grain and particles begin to distort your image and result in a loss of detail. This phenomenon is called digital noise!
For this reason, it is essential to know what value makes your picture look better or worse.

Here are some examples :

Some cameras can even reach an ISO level of 102,400 which is ridiculously high.

Chances are you will never have to crank yours up higher than 12800. A sweet spot that I’ve found works best in dark conditions without distorting the image too dramatically is 3200. There will be situations where you’ll need to go higher than this, but unless you’re shooting in a VERY dark environment, you should be able to keep it at 3200 or lower.



Best practice would be to always use your lowest ISO camera setting, to get the optimal image quality. However, it is not always possible especially if you need to shoot a moving subject in low light condition. Indeed, worse than having a noisy picture is having a blurry picture! Noise can always be reduced in post-production, Blur can’t!

Options are, if you can, to use a wider aperture or – if your subject is still – a tripod. These two options help you to photograph in a low-light situation and keep your image quality optimal.
If you have neither, then cranking up your ISO is your only solution. After all, it’s better to have a noisy picture than no picture right?

You can find more information about the relation between ISO, Aperture and Shutter speed by reading this article: “Exposure triangle: ISO, Aperture ans Shutter Speed working together!” (coming soon)

Recap: ISO is your cameras internal brightness. It’s used to brighten up a photo that is being taken in low-light condition.

Get rid of the noise: The easiest way is to get your RAW image through post-production software like Lightroom, DxO Photolab or Luminar. If you need more information about the RAW format you can read this article: RAW vs JPEG: What are the advantages of a RAW image?


Here’s something you can practice right now

Practice is the easiest way to learn, therefore, grab your camera and play around with the ISO settings.

Take pictures in a dark room, a dimly light room, a well-lit room, and a very bright room. See how the setting changes your exposure. After taking pictures with the different values compare them on your computer. See how cranking the amount up affect your images.

If your camera’s ISO is at its lowest setting and the picture is still too bright, then this means you need to adjust your aperture and/or shutter speed. Read these articles to discover more:

Don’t forget, practice is the key!