What type of lighting condition usually requires a higher ISO to compensate for low light?

The type of lighting condition that typically necessitates a higher ISO to compensate for low light is heavy overcast. In overcast conditions, the sky is often filled with thick clouds that diffuse sunlight, resulting in a softer, more muted light. This can significantly reduce the overall light available for photography, requiring adjustments to the camera settings to maintain an appropriate exposure.

Using a higher ISO setting increases the sensor's sensitivity to light, allowing the photographer to capture images effectively in these lower-light conditions. While other factors like aperture and shutter speed can also be adjusted, increasing the ISO is a common and effective way to counteract the lack of light under heavy overcast skies.

In contrast, bright sunshine provides an abundance of light, which allows for lower ISO settings. Fluorescent lighting can sometimes result in tricky color tones and requires careful white balancing rather than adjustments to ISO. Lastly, soft shadows typically occur under diffused light conditions but do not inherently indicate low light levels that would require elevated ISO settings.