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What is ISO in photography? All you need to know!

Taking good photos is not always an easy task, as it requires practice, artistic sensitivity and a little knowledge. Thinking about the latter, let's explore what the ISO is in the photographs!

Taking relatively simple photos, since virtually all smartphones have cameras to make recordings and videos. However, an image that draws attention depends on combined technical and artistic factors.

Speaking of the artistic part involves subjective values, but if we speak purely of the technique, there are three fundamental elements that a beginner photographer needs to know about his camera: aperture, speed and ISO.

The three need to work simultaneously for a quality image, requiring knowledge of the photographer, who often needs to ?juggle? due to the conditions that the environment provides.

With that in mind, we will explore a little more about the ISO in the photographs. Be sure to also check out our article on 3 mistakes that (almost) everyone makes when taking a photo.

A little history

The word "ISO?Appeared in 1974 from ?International Organization for Standardization? (International Organization for Standardization, in free translation) to standardize the system in cameras around the world.

They decided to change the letters ?S? and ?O? from place to refer to the Greek word ?iso?, which means ?equal?. In the beginning, the ISO it was measurable by the sensitivity to light of the films, and it was written on the label, as in the image above.

In converting to the digital world, the ISO became the sensitivity of the sensor from the light camera, which in most cases has a minimum value of 100 (low sensitivity) to 16,000 (high sensitivity) or even more.

This means that the better illuminated the environment, less ISO required.

In practice, how does ISO affect the image?

In a well-lit environment, the ideal ISO as little as possible to avoid noise and grainy images. Therefore, the rule: the lower the ISO, greater quality.

Comparative photo with the amount of ISONotice in the image that the higher the ISO, the more grainy it gets (Image: Fstoppers)

The above image is a clear example that an excessive amount of light entering the camera lens causes the image to lose its quality. Notice that in the rectangle ISO 3200 the image completely clear, while in the ISO 50000 the sky is entirely granulated.

In this one, the Darth Vader doll was in a dimly lit environment, and in that case, a higher ISO was needed to be able to see it more Details.

It is worth mentioning that the camera itself also influences quality, as there are professional models nowadays where you can have a ISO relatively high without losing definition.

Finally, there are cases where the photographer leaves the ISO purposefully loud wanting to convey some kind of message artistic.

Can I remove the noise in the post-edio?

Programs like Adobe Lightroom or Photoshop allow you to make adjustments to lighting, colors, noise and grain. The last mentioned, for example, has filters that reduce noise and you can increase or decrease the intensity yourself according to your preferences.

However, as much as it improves the quality of the image, it still does not have the same definition as a photograph taken with the value of ISO low.

Aperture and Shutter speed

As stated before, these two elements work together with the ISO, and a specific article is worth each one. However, it is important to have a sense of how they work.


Just as the pupil in our eyes increases or decreases according to the light entering the environment, the opening of the diaphragm works in a similar way. The lower the number "F" (Fraction), the more open the diaphragm is and, therefore, the more light enters to make the image.

In practice, the larger the aperture, the smaller the depth of field. Which means that the background images are distorted, as in the photo above.

Shutter speed

As the name suggests, this is the time when the sensor ?sees? the scene you want to capture. Do you know those ?shaky? images that everyone has already taken? They are the result of a slow shutter speed.

The speed scale by ?fractions of a second?And the higher the denominator, the faster the image is captured. That is, 1/500, for example, is much faster than 1/30.

However, with the aid of a trip, it is possible to create beautiful photos with low shutter speed.

As we see in the comparative photo above, the image on the left was taken at high speed, while the one on the right came at low speed.

Creativity and personal style

The important thing, especially for beginners in photography, is that the image is as clear as possible, reflecting the colors and lighting that ?your eyes? see.

There is no specific rule for how this will be done, but the idea is to have a balance between ISO, shutter speed and aperture. Be creative using these three elements and good photos!