400W HMI

400W HMI daylight-balanced discharge lamp fixture; includes models like K5600 Joker 400 or Arri Arrilux Pocket PAR 400.

Overview

"400W HMI" does not refer to a single fixture, but rather a power class of daylight-balanced HMI lights with a lamp output of 400 watts. HMI stands for Hydrargyrum Medium-Arc Iodide – a discharge lamp where an arc is ignited between two electrodes in a bulb filled with mercury and metal halides. Like all HMI lamps, the 400-watt version also requires a ballast to ignite the arc and regulate the current; it cannot be connected directly to mains voltage.

The 400-watt class is a standard format for compact daylight units on set. Common fixtures in this class include the K5600 Joker 400 / Joker-Bug 400, the Arri Arrilux Pocket PAR 400, the Bron Kobold DW 400, and the Mole-Richardson DigiMole 400W. Despite different designs, these fixtures use the same lamp type.

Technical Specifications

Feature	Specification
Lamp Power	400 W
Light Character	Daylight (HMI typical approx. 5600 K)
Lamp Type	Single-ended discharge lamp (e.g., MSR 400 HR, GZZ 9.5 base)
Ballast	Required (magnetic or electronic/flicker-free)
Hot Restrike	Possible (re-ignition when hot)

HMI lamps produce significantly more light per watt than Tungsten/Halogen and are therefore considered efficient daylight sources. Specific lamp data vary depending on the manufacturer and model – for the Joker-400 system, K5600 specifies a current draw of around 5.5 amps and a light output comparable to a 1500/2000W quartz fixture.

On-Set Usage

400-watt HMIs are used when daylight-colored light with relatively high "punch" is needed in confined spaces – for example, as a light source through a small window or as a compact accent light. Due to their low power consumption, they can often be operated from a standard outlet, unlike higher-powered HMI heads.

The Joker-400 system includes a set of interchangeable lenses (e.g., Frosted Fresnel, Super-Wide, Wide, and Medium Flood), allowing the beam to be varied between soft Fresnel light and a focused PAR spot. When working with cameras, it is important to use a flicker-free electronic ballast or an operating mode synchronized with the frame rate.

From the crafts

Perspectives

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.

Producer

This professional solution increases production efficiency and reduces post-production requirements. It allows for flexible, quick 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.