digital camera iso

Understanding camera ISO

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Just for a recap, do you remember the three key elements that are the core of photography and work together with each other in every photo to create an “exposure?”

Yes, these are ISO, Shutter-Speed, and Aperture, commonly remembered through the exposure triangle. So as you all know, it is paramount for every photographer to understand the workings of these three components completely, how they interact with each other, and how they impact the exposure to become a proficient photographer.

That is why today, we will provide you with an in-depth explanation of one of these elements. The ISO. This element has become the most vital component of digital photography and is used most by the photographers.

Camera ISO

We have chosen ISO because it plays a very important role in the exposure triangle, so here are some tips and tricks to use ISO creatively so that you can technically create a proper exposure.


At first, ISO was used in film photography days to define a film’s sensitivity to light. It was used to make film photography look less grainy, but today the term has evolved and stepped into the world of digital cameras, but the concepts remain the same.

What is ISO?

ISO or ASA refers to the sensitivity of the camera’s sensor to light. There is a direct correlation between Exposure and ISO – the lower the ISO number, the lower the camera’s sensor will be less sensitive to light, and the higher the number, the. There will be more as the camera’s sensor will be highly sensitive to light.

So basically, this means that if you want less grainy and clear pictures, then use a lower ISO but if you want to add an artistic effect to your pictures by adding a little noise, then raise your ISO.

The link between ISO and shutter speed

Secondly, there is a deep connection between shutter speed and ISO as well. This is because if the ISO number is high and the sensor is more sensitive to light, you can pair it with fast the shutter speed to get a proper exposure.

iso camera

So if you are worried about getting blurry photos, then just check that your shutter-speed and ISO settings complement each other, as explained in this article, and your images will come out tack sharp.

Some examples:

Here in the first situation, you are shooting in the middle of the day, which means it is most likely that you will have plenty of daylight. So, in this case, you will have to ensure that your ISO is as low as possible. This will result in the cleanest image, which will not only be noise-free but will also have the most dynamic range and depth of color.

In the second situation, you want to emulate an older look by making the photograph feel taken on film, having a grainy appeal. High ISO numbers will add a little noise, which will produce an artistic effect.

You can add grain in post-processing, but you won’t get the same look, so it is better to experiment with ISO.

When to consider changing ISO

ISO is usually changed when one of the other components of the exposure triangle is altered. So to maintain the exposure, you have to change the ISO in the opposite direction. In most cases, ISO is changed concerning shutter speed to provide more light.

Aperture vs. ISO

If your shutter speed is slow, but you want a better exposure, you have a choice between raising ISO and widening the aperture to get a better image. So in the above situation, the photographer has to create a subjective balance, and for that, he/she has to decide to select either wider apertures or higher ISO.

digital camera iso

This tradeoff will likely depend on the subject being photographed and the circumstances as they are the most important factors that impact your image and lead to selecting one route or the other.

For example, if you are conducting a family portrait session in the shade, and your shutter speed is only 1/50th on the 50 f1.4 lens, it pushes the limits. It will easily blur the subjects if they slightly move or even if you don’t hold the camera still enough.

Thus, to get more light in the shade, you have to make the trade-off to lower the aperture to widen the opening for more light to pass or raise the ISO to make the camera more sensitive to light.

These both will enhance exposure, but only one can be chosen at the expense of others. Whichever you chose, there will be some pitfalls because if you widen the aperture, it will result in less depth of field, and if you raise the ISO, it will lead to more grain and noise.

Some situations where high ISO is required:

  • Wedding Ceremonies that take place in Churches where flash is not allowed
  • Concerts and events that have lots of movement
  • When capturing Birds in flight with long telephoto lenses as usually, they require extra fast shutter speeds.
  • For Sports actions that have fast movements and require telephoto lenses with fast shutter speeds
  • When making use of “zoom kit-lens,” as they don’t have wide apertures, so for the compensation, you have to make use of higher ISO numbers.


No matter what you do, if you cannot grasp the concept of ISO and cannot use it properly, then your photographs will always lack a professional outlook. This is because, in today’s camera, ISO has become a vital component, and the best of the best photographers use it to make their results look extraordinary.

Remember, anybody can click a photograph, but you have to master the settings to add magic to it. It is the choice of settings that differentiate a breathtaking photograph from a normal photograph.

So, to make the right choice, you have to understand the digital photography settings, and amongst the basic components is ISO, which needs to be mastered as it can take you a long way.

It might look a bit too much to grasp right now, but once you start practicing, it will become easy as practice makes you perfect. So now it’s your turn to go out and start applying what you have learned and do wonders to your photography skills by adding a touch of ISO to it!

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  1. Pingback: Manfrotto 190X review – GottaPics

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