The practice of 'warming' the filament of a conventional lantern. Partly to avoid damage to the lamp by suddenly flashing to full, but also to create smoother fades.

Some Lighting Desks (such as the strand 500-series) allow you to specify a preheat level in the desk which will then automatically be used to warm the lamps used in the following cues, while many dimmers also have a preheat function which basically sets a minimum level for the output of the rack.

Care must be taken when using pre-heat functions that the level is not set too high as you can end up with the stage being bathed in an orange glow during black-outs if you are not careful!

See Also

• Topset
• Dimmer Laws

• Discussion