Norman Lamps, Inc.

HPL halogen lamps are specialized high-performance theatrical lighting lamps with specific characteristics engineered for ellipsoidal reflector spotlights (ERS) commonly known as "lekos" in the entertainment lighting industry. These aren't ordinary bulbs – they're precision-manufactured lamps designed to work with the optical systems of professional stage lighting fixtures, providing the intense, controllable beams of light that illuminate performers, sets, and specific stage areas in theaters, concert venues, houses of worship, and other performance spaces.

The HPL designation encompasses a family of lamps with different wattages (375W, 550W, 575W, 750W) all sharing the same compact bipost base (P28s) and similar physical dimensions, allowing lighting designers to select appropriate wattage for different throw distances and desired intensities while using the same fixtures. This interchangeability is valuable in production environments where the same fixtures might be used for different shows or different positions requiring different light levels. The compact filament design creates nearly point-source light that works efficiently with the ellipsoidal reflectors and lens trains in ERS fixtures.

Color temperature in HPL lamps runs around 3050K at rated voltage, producing warm white light that renders skin tones attractively and works well with the color filters (gels) commonly used in theatrical lighting. The color rendering is excellent at CRI 100, essential for theatrical applications where costumes, makeup, and scenery must appear as the designer intended. The spectral characteristics of tungsten halogen light work predictably with theatrical gels, allowing lighting designers to achieve precise color effects.

Operating life for HPL lamps averages 300-400 hours when operated at full voltage – quite short compared to general lighting lamps but typical for high-intensity theatrical lamps running filaments at extreme temperatures for maximum light output. Many theatrical productions dim lighting fixtures to extend lamp life and achieve desired intensity levels; operating HPL lamps at 90% of rated voltage can extend life to 700-1,000 hours while producing only slightly less light output. This dimming to extend life is common practice in installations where lamps run many hours.

The rated lumens and beam characteristics of HPL lamps are optimized for use in ellipsoidal fixtures with specific reflector designs. These aren't lamps you'd use in standard household or commercial fixtures – they're designed specifically for theatrical instruments. The compact bipost base provides secure mounting and good electrical contact while surviving the heat and vibration common in theatrical fixtures. The base orientation is indexed so the lamp can only be installed in the correct rotational position, ensuring the filament aligns properly with the fixture's reflector.

Handling HPL lamps requires care: never touch the quartz envelope with bare hands as oils from skin create hot spots that lead to premature failure. If you do touch the envelope, clean it with alcohol before use. Ensure the lamp is fully seated in its socket and the lamp cap is properly secured before powering on. Allow adequate cooling time before removing a lamp that's been operating. These lamps get extremely hot during operation and retain heat for several minutes after being switched off.

Replacement intervals in professional settings are often scheduled rather than waiting for failure, particularly before critical performances where lamp failure would be disruptive. Many venues replace lamps that have reached 70-80% of rated life as preventive maintenance, especially in positions that are difficult to access. The relatively high cost of HPL lamps compared to general lighting is simply accepted as part of theatrical lighting budgets.

LED alternatives to HPL lamps are gradually entering the theatrical market in the form of LED ellipsoidal fixtures. These offer dramatic energy savings, virtually no heat output, and exceptionally long life. However, traditional HPL-based fixtures remain prevalent due to the excellent color rendering, smooth dimming behavior, and familiar light quality that lighting designers and directors have worked with for decades. The transition from HPL to LED in theatrical lighting is happening gradually rather than rapidly.

Common Wattages: HPL 375W, HPL 550W, HPL 575W, HPL 750W. All use same P28s bipost base for interchangeability.

Base Type: P28s compact bipost - indexed for correct orientation

Rated Life: 300-400 hours at full voltage, 700-1,000 hours when dimmed to 90% voltage

Applications: Ellipsoidal reflector spotlights (ERS/leko) in theaters, concert venues, houses of worship, television studios, any professional performance lighting requiring precise beam control