When would it be necessary to increase the ISO setting on a camera?

Increasing the ISO setting on a camera is particularly necessary in low-light conditions without the use of a flash. The ISO value indicates the sensitivity of the camera's sensor to light; a higher ISO allows the sensor to detect light more efficiently, which is essential in situations where there isn't enough natural light to achieve proper exposure.

In scenarios with limited lighting, raising the ISO will help to avoid underexposure, enabling you to capture images that are adequately lit. This technique is vital for maintaining image quality in dim environments, such as indoor spaces or at night, where additional light sources are not available.

While adjusting the ISO does allow for brighter images, it's important to consider the trade-offs; increasing ISO can introduce noise or graininess to the images. Thus, photographers often seek to balance ISO settings with other parameters like aperture and shutter speed, depending on the specific conditions and artistic intentions of their work.

In comparison, capturing fast-moving objects generally requires a fast shutter speed rather than an increased ISO. Similarly, bright outdoor conditions would call for a reduced ISO to prevent overexposure, and achieving a high depth of field typically involves adjusting the aperture rather than the ISO setting.