Dimmers can be used on location to enable:
Tungsten sources change their colour when dimmed (refer to p. 76 for a discussion on this topic). Fluorescent sources may have a dimmer integral with the lamp ballast. When dimmed the fluorescent light does not change its colour significantly.
Dimming control may be by:
HMI/MSR sources using flicker-free ballasts have an integral dimmer with a local dimming control 100–50%. However, the change in colour with dimming may not be tolerable. Consequently, these sources should be fitted with a mechanical dimmer (shutter) ...