A photographic film exposure consists of four basic variables. Which of the following is NOT one of those variables?

In the context of photographic film exposure, the four basic variables that affect the exposure of an image are the subject light, camera lens aperture setting, camera shutter speed setting, and film sensitivity (often referred to in the context of digital photography as ISO). These variables work together to determine the exposure, which impacts how light influences the film or sensor.

Film development time, while crucial in the overall photographic process, does not fit into the category of exposure variables. This is because film development happens after the exposure has taken place, affecting the final image quality but not influencing the initial exposure itself. Thus, it stands out as the option that is not directly involved in the exposure process.

Understanding the distinction between the exposure variables and the development process is essential for mastering photographic techniques, particularly in the context of latent print analysis where precise control of exposure variables is vital for optimal results.