9000W HMI

Overview

"9000W HMI" refers to the 9-kilowatt power class of daylight discharge lamps (HMI = Hydrargyrum Medium-Arc Iodide). In practice on a film set, the term is largely synonymous with the ARRI M90 from the M-Series, by far the most common fixture of this wattage. Additionally, "9000W HMI" also refers to the associated lamp specification: a single-ended HMI lamp with a GX38 base, such as the "HMI 9000W/SE/XS" manufactured by Osram.

The M90 is a lensless open-face fixture with ARRI's faceted MAX Technology reflector, which combines the characteristics of Fresnel and PAR lights. According to ARRI, it bridges the gap between the M40 and the ARRIMAX 18/12 and, from a 9000-watt burner, delivers an output in the order of a classic 12kW PAR – in a significantly more compact form factor.

Technical Data (ARRI M90)

The M90 is mechanically and electrically compatible with the 6kW infrastructure: it uses existing 6kW cables, and the 9000W burner is structurally very similar to the 6000W lamp, allowing the same reflector to function at both wattages.

Set Usage

As a powerful daylight fixture, the 9kW class is used for large-area fill light, simulating daylight through windows, hard sun imitation, and for long throws – for example, as a more compact alternative where a 12K PAR would be too large or too heavy. Via the high-speed ballast (1000 Hz), the light remains flicker-free even for high-speed shots.

• The lensless reflector produces a uniform light field with a clear, sharp shadow and eliminates the need for spread lenses, accelerating set workflow.
• Color and diffusion gels (e.g., CTO, diffusion) are applied to the barndoor or via scrims, as with other open-face HMIs.
• Due to its weight, heat generation, and power consumption, the head is typically a grip/electric department job on an appropriate stand or combo stand with a separate ballast.

Lamps are treated as consumables: single-ended 9000W HMI lamps from various manufacturers (Osram, Koto, etc.) differ in color temperature, lumens, and lifespan; the respective manufacturer data sheets are always binding.