CTB-003 Color Temperature Blue (Cooling) Filter

CTB-003 provides a gentle “cool-blue” lift—about 1⁄8 CTB—for situations where you want to nudge a warm source a few hundred kelvin cooler without sacrificing much output. The coating transmits roughly 87.6 % around 433 nm, slopes gradually to ~65 % at 510 nm, and settles near 57 % by 600 nm. Red energy tapers only mildly, staying above 50 % through the far-red, so skin tones remain natural rather than drifting toward cyan. Use it to fine-tune tungsten, halogen, or warm-white LED fixtures for mixed-light scenes where full CTB would be too aggressive.

Key advantages

• Subtle 1⁄8 CTB shift – Raises CCT by ≈ 300–400 K, perfect for balancing tungsten with cool LED fills.

• High blue-region throughput – ≥ 80 % between 420–460 nm means minimal brightness loss.

• Smooth spectral roll-off – No sharp notches that would skew colour rendering or add a green cast.

• Heat-tolerant oxide stack – Handles 1 kW tungsten and high-power LEDs where plastic gels can bubble.

• Custom formats – Round, square, or free-form blanks from 5 mm to 450 mm, 0.21–3.8 mm thick, on Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG glass.

Typical applications

• Stage & architectural lighting – Slightly cool house tungsten rigs to match cooler LED video walls.

• Film & broadcast – Bring practical lamps a shade bluer so they grade smoothly with daylight units.

• Photography modifiers – Fine-tune strobes for mixed environments without stacking multiple gels.

• Museum & retail displays – Lift CCT for whiter whites while keeping UV well below conservation limits.

• Inspection & machine vision – Enhance blue-channel contrast when reading optical brighteners or security inks.

Need a prototype this week or a production batch next month? CTB-003 filters can be coated, cut, and shipped to your exact spec—fast.