Darkroom environmental condition combination recommended?

• A. 75-85F and 30% RH
• B. 50-60F and 70% RH
• C. 65-70F and 50% RH
• D. 60-65F and 40% RH

Answer: (C)

Controlling darkroom temperature and humidity is about balancing film quality, processing consistency, and handling safety. A mid-range temperature around 65–70°F keeps the developer activity predictable: not so hot that chemical reactions run too fast (causing fog or overdevelopment) and not so cold that development slows and becomes inconsistent. Relative humidity around 50% minimizes static electricity when handling film, which reduces unlikely film marks, while also avoiding excessive moisture that could promote condensation, mold, or chemical issues. This combination—65–70°F with about 50% RH—provides a stable, workable environment that supports consistent processing and reduces the common environmental problems seen in darkrooms. The other options either push the temperature too high or too low or place humidity in ranges that increase static, condensation, or mold risks, making them less ideal for reliable film handling and processing.