HMI DE

Overview

HMI DE stands for a double-ended HMI lamp. HMI refers to a metal halide discharge lamp (Hydrargyrum Medium-arc Iodide) that produces daylight-like light on film sets. The abbreviation DE does not describe a separate lighting technology, but rather the design of the light source: the quartz burner has an electrical contact (base) at both ends, in contrast to the single-ended variant HMI SE (Single-Ended), which has only one base.

Like all HMI lamps, an HMI DE lamp requires an external ballast, which ignites the arc and limits the current; the burner cannot be operated directly from the mains.

Design and Base

The double-ended design is a straight quartz tube with a base on the left and right, which is clamped horizontally between two contact holders in the fixture. Typical base types are Bipin/Pin bases of the SFc or SFa series (and more robust bases for very large lamps). Single-ended (SE) lamps, on the other hand, sit in a single base at the rear end of the burner.

• HMI DE: compact, straight burner with two end contacts; common in PAR fixtures and open (non-Fresnel) heads.
• HMI SE: single base; structurally typical for Fresnel heads.

Use on Set

HMI DE lamps deliver daylight-like light (manufacturer specifications around 5600–6000 K) with high color rendering (CRI >90 for OSRAM's HMI line) and are used for fill light, as artificial suns, and for window light. Important handling considerations:

• Orientation: The discharge/pump-out tip of the burner should point upwards whenever possible, so that deposits do not accumulate at the coldest point during cooling.
• Gloves: Never touch the quartz envelope with bare fingers – skin oils cause devitrification and can destroy the lamp prematurely.
• Color Temperature Over Lifespan: New burners start significantly cooler/bluer and only approach their nominal color temperature after the first few hours of operation.