What is the recommended height for a safelight when measured from the loading bench?

The recommended height for a safelight when measured from the loading bench is commonly set at 4 feet. This standard height helps to ensure that the light does not adversely affect sensitive photographic materials while still providing sufficient illumination for the technician to work effectively.

Positioning the safelight at this height minimizes the risk of fogging or exposure of light-sensitive materials, as it allows the technician to work without being in direct light, thereby providing an optimal environment for loading film or handling photographic paper. Additionally, the 4-foot height typically aligns with ergonomic considerations, allowing a comfortable working posture without the need for excessive bending or stretching.

In contrast, heights that are too low may expose the materials to more direct light than necessary, whereas heights that are too high might make it difficult for the technician to see clearly. This balance between safety and usability is crucial in a darkroom setting, validating the preference for a 4-foot height for safelighting.