How often should darkroom fog be tested?

How often should darkroom fog be tested?

• A. Monthly
• B. Quarterly
• C. Semi-annually
• D. Annually

Answer: (C)

Darkroom fog testing is a QA check to ensure the safelight isn’t fogging film. The safelight, bulb aging, or filter changes can gradually affect film density, so you want a regular, practical interval that catches drift without overdoing it. Six months gives a balance: it’s frequent enough to catch gradual degradation or changes in safelight performance, but not so frequent that routine operations are bogged down with testing. If you replace a safelight bulb or filter, or if you notice any signs of fogging, test sooner. Monthly would be unnecessarily burdensome for gradual changes, and quarterly or annual intervals could miss creeping problems.

Darkroom fog testing is a QA check to ensure the safelight isn’t fogging film. The safelight, bulb aging, or filter changes can gradually affect film density, so you want a regular, practical interval that catches drift without overdoing it. Six months gives a balance: it’s frequent enough to catch gradual degradation or changes in safelight performance, but not so frequent that routine operations are bogged down with testing. If you replace a safelight bulb or filter, or if you notice any signs of fogging, test sooner. Monthly would be unnecessarily burdensome for gradual changes, and quarterly or annual intervals could miss creeping problems.