CTB-003 Color Temperature Blue (Cooling) Filter

⅛-CTB glass filter: lifts warm sources ~300–400 K cooler with ≥ 80 % blue throughput and a gentle red roll-off—perfect for subtle daylight balance.

Blue boost: 420 – 460 nm ≥ 80 % T (peak ≈ 87.6 % @ 433 nm)
Spectral slope: ~65 % T @ 510 nm → ~57 % T @ 600 nm
Red retention: > 50 % T through far-red (≥ 650 nm)
CCT shift: +300 – 400 K (⅛-CTB)
Construction: Ion-assisted hard-oxide; 5 – 450 mm, 0.21 – 3.8 mm thick
Custom options: AOI tuning, ripple flattening, rapid prototypes

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CTB-003 gives a gentle “cool-blue” lift—about ⅛ CTB—nudging tungsten or warm-white LEDs a few hundred kelvin toward daylight without the heavy output loss of full CTB gels. The coating transmits ~87 % at 433 nm, rolls 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 cyan-shifted.

KUPO coats Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG substrates cut to any outline—from 5 mm chips to 450 mm plates—with thicknesses of 0.21 – 3.8 mm, and can ship prototypes in around two weeks.

Typical uses: subtle CTB on stage rigs, balancing practical lamps on film sets, cooling photo strobes, museum lighting with low UV, and machine-vision tasks needing a blue boost without large brightness loss.

$88,888.00

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Description

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.