Reciprocity failure can affect which type of cameras?

Reciprocity failure refers to the phenomenon where the expected exposure time based on the relationship between aperture, shutter speed, and ISO does not work properly in very long or very short exposure times. This failure is predominantly applicable to film cameras, particularly because film has a different response curve to light compared to digital sensors.

In film photography, different films react inconsistently at extreme exposure times, requiring photographers to compensate by adjusting exposure settings in ways not anticipated by the typical exposure triangle. As a result, film cameras can experience issues with exposure when images are captured under unusual lighting conditions or for extended durations.

Digital cameras, including mirrorless and point-and-shoot types, utilize sensors that tend to handle long and short exposures more reliably due to their electronic nature. These cameras have algorithms designed to compensate for exposure changes, thus mitigating the impact of reciprocity failure. Therefore, the concept of reciprocity failure is primarily relevant to all film cameras as they rely on chemical processes that may not respond consistently across the full range of exposure settings.