CTB-009 Color Temperature Blue (Cooling) Filter

CTB-009 achieves a noticeable yet manageable ~1/2 CTB-equivalent shift via a more aggressive spectral separation between blue and warm light. Blue transmission stands at 79 %, while red plunges to 48.9 %-a 1.62 blue-to-red ratio that visibly cools incandescent light toward daylight without overshooting. The broader UV passband (81.6 %) and well-defined valley in the yellow-orange region (49 % at 593 nm) create a decisive color temperature change suitable for professional color correction in broadcast and film environments.

Key Advantages

• 1.62 Blue-to-Red Decoupling - Genuine ~1/2 CTB equivalent without resorting to multi-layer stacks-achieves measurable color temperature shift in a single, lightweight element.
• Steep Yellow-Orange Suppression - Yellow dips to 49 % at 593 nm-eliminates the warmest, most visible portion of tungsten spectrum for precision color correction.
• Hard-Oxide Ion-Assisted Coating - Resists abrasion and thermal stress from production lighting rigs-maintains performance through dust, moisture, and repeated thermal cycling.
• 79 % Blue Passband Efficiency - Retains sufficient brightness for key and fill lights even after filtration-minimizes need for increased fixture wattage or longer exposure times.
• Custom Formats and Substrates - Available in round, square, and free-form blanks from 5 mm to 450 mm, thickness 0.21-3.8 mm on Borofloat, soda-lime, Schott D263 T, or Corning Eagle XG.

Typical Applications

• Broadcast Color Correction - Correct tungsten studio lighting toward daylight 5600K without the color casts of gel combinations, yielding cleaner sensor response.
• Film Set Lighting Design - Achieve intentional cool-tone mood lighting by filtering tungsten practicals or key lights during principal photography.
• Machine Vision White-Balance Calibration - Serve as a repeatable color reference standard for industrial inspection systems that must function under mixed warm and daylight illumination.
• Architectural Facade Lighting - Transform warm tungsten or halogen floodlights into cooler accent lighting for modern glass and steel buildings without switching fixture types.
• Concert and Live Event Production - Combine with other color filters to create multi-toned stage washes that blend tungsten wash lights with LED cool tones seamlessly.

Fast turnaround prototypes and full production capacity for live event, broadcast, and film workflows. Specify dimensions, substrate, and edge requirements.