ISO is the unit for the light sensitivity of a camera's recording medium. For analogue cameras, ISO refers to the sensitivity of the film, while for digital cameras it refers to the sensitivity of the image sensor.

The higher the ISO value, the more light-sensitive the sensor or film is. A higher ISO value makes it possible to take clear pictures in low light conditions, such as in the evening or at night.


  • Shooting in low light: With higher ISO values, photographers can also take pictures in low light conditions without additional light.
  • Shorter exposure times: A higher ISO value can lead to shorter exposure times, which is particularly advantageous when taking pictures of fast-moving objects or for freehand photography.


  • Image noise: Higher ISO values can lead to increased image noise, which becomes visible as a disturbing, grainy pattern.
  • Reduced image quality: In addition to image noise, the sharpness and detail of the images can also decrease at high ISO values.

Areas of application:

  • Low ISO values (100-400): Ideal for bright lighting conditions, such as in daylight or in the studio, to achieve maximum image quality with minimum noise.
  • Medium ISO values (400-1600): Suitable for indoor shots or cloudy days where a little more light sensitivity is required.
  • High ISO values (1600+): Useful for very low light conditions, such as night shots, concerts or interiors without additional lighting.

ISO is a key parameter in photography that controls the light sensitivity of the recording medium. While higher ISO values enable photography in poor lighting conditions, they are often accompanied by an increase in image noise and reduced image quality. The conscious choice of ISO value is therefore crucial for image composition and quality.


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