Cinematographer
From a DoP's perspective, this element is essential for the visual design. It allows me to consistently implement the desired color mood and aesthetic image.
1200W HMI daylight fixture with metal halide discharge lamp, available as PAR or Fresnel, powered by integral electronic ballast.
Overview
"1200W HMI" refers not to a single manufacturer's fixture, but to a power class of daylight fixtures based on the HMI discharge lamp. HMI stands for Hydrargyrum Medium-arc Iodide – a metal halide high-intensity discharge lamp with a color temperature in the daylight range. The 1200-watt variant, alongside 575 W, 2.5 kW, and 4 kW, is one of the most common sizes on film and TV sets and is offered in two designs: as a PAR and as a Fresnel fixture (e.g., ARRI ARRISUN 12 as PAR and True Blue D12 as Fresnel, as well as units from Mole-Richardson, FilmGear, and others).
Unlike an incandescent lamp or an LED panel, an HMI fixture always requires a separate electronic ballast. This ignites the lamp with high voltage and then stabilizes the arc. Modern electronic ballasts operate flicker-free, allowing for high camera frame rates.
Technical Data
The following values refer to typical 1200W HMI lamps and heads from common manufacturers; they vary depending on the model.
| Characteristic | Typical Value |
|---|---|
| Power | 1200 W |
| Color Temperature | approx. 6000 K (daylight balanced) |
| Lamp Base (single-ended) | G38 |
| Luminous Flux (lamp) | approx. 110,000 lm |
| Lamp Life | approx. 1000 h |
| Operation | only with electronic ballast (575/1200 W), flicker-free |
Common lamp types in this class include the OSRAM HMI 1200 W/SE or HMI Digital 1200 W/SE, the Philips MSR 1200 HR, and the GE CSR 1200/SE/HR – largely identical and interchangeable among them. Single-ended lamps (SE) use a G38 base; double-ended versions also exist.
On-Set Use
The 1200W HMI is a classic daylight workhorse. Due to its high luminous efficacy per watt, it delivers significantly more usable daylight than a comparable tungsten fixture and is therefore often referred to as a "mini-sun." Typical applications:
- Day Exterior Fill: Lighting up shadows during exterior shoots without altering the color temperature of sunlight.
- Window Light / Day Interior: as a powerful daylight source through windows or as a bounce.
- Key Light in Daylight Setups: the PAR version with a set of diffusion lenses (lens set from spot to wide) provides a hard, far-reaching beam; the Fresnel version allows for continuously focusable light from spot to flood.
Practical notes: HMI lamps are pressurized and get very hot during operation – replacement should only be done when the lamp is cool and handled with gloves if possible. Older lamps may flicker or drift in color; UV-stop lamps reduce UV radiation. Lamp and ballast should be matched in terms of wattage (575/1200W ballasts are often switchable).
From the crafts
Perspectives
Producer
This professional solution increases production efficiency and reduces post-production requirements. It allows for flexible, fast adjustments during the shoot.
Gaffer
As a gaffer, this is an indispensable tool in my daily toolkit. It allows me professional light control and quick adjustments on set, which saves time and ensures quality.
More in the lexikon
Related terms
Test your knowledge
Quiz
1. Zu welchem Department gehört „1200W HMI"?
2. Wie viele verschiedene Fachperspektiven bietet dieser Eintrag?