ISO in photography refers to the sensitivity of the camera’s image sensor to light. The ISO setting determines how much light is needed for a proper exposure and affects the brightness and noise level of the resulting image.
In digital cameras, ISO is a numerical value that typically ranges from 100 to 6400 or higher. A lower ISO setting, such as 100, is less sensitive to light and requires more light to produce a proper exposure, while a higher ISO setting, such as 6400, is more sensitive to light and requires less light to produce a proper exposure.
In poor light, increasing the ISO setting can be helpful because it enables you to use a faster shutter speed or a smaller aperture to get the right exposure. Higher ISO settings, though, can also make the picture look grainier or noisier due to digital noise.
Therefore, depending on the lighting and intended effect of their photograph, photographers should select the proper ISO setting. Along with the aperture and shutter speed, ISO is one of the three important settings that affect how well-exposed a picture is. Shutter speed is the amount of time the camera’s shutter is open so that light can reach the image sensor, whereas aperture refers to the opening in the lens that controls how much light reaches the camera.
The sensitivity of the picture sensor to light is depicted on a scale by ISO. An ISO of 200 is twice as sensitive as an ISO of 100, an ISO of 400 is twice as sensitive as an ISO of 200, and so on. The scale is typically increased for each increment. You might need to raise your ISO level when shooting in low light conditions to let more light into the camera. This can assist you in preventing the use of a slow shutter speed, which could lead to blurry pictures from camera shake, or a wide aperture, which could lead to a shallow depth of field. However, as you raise your ISO level, you run the risk of adding more grain or digital noise to your photos.
In contrast, you might want to reduce your ISO when shooting in bright sunlight to prevent overexposure, or to enable a slower shutter speed or a wider aperture. The amount of noise at high ISO settings has been much reduced by modern cameras, but it is still something to be aware of and take into account when choosing your ISO setting. To find out how high you can set your camera’s ISO before the noise in your photographs becomes too pronounced, it’s vital to test your camera’s performance at various ISO settings.