CTB-002 Color Correction Filter
¼-CTB glass filter: boosts blue (430 nm ≈ 85 % T) while trimming amber/red, nudging tungsten or warm-white LEDs ~900 K cooler without heavy light loss.
- Blue region: 430 nm ≈ 85 % T; ≥ 55 % T to 510 nm
- Red roll-off: < 40 % T @ 600 nm → ~28 % through far-red
- CCT shift: +800 – 1 000 K (¼-CTB)
- Coating: Ion-assisted hard-oxide; single-surface, low ripple
- Formats: 5 – 450 mm shapes, 0.21 – 3.8 mm thick (Borofloat®, soda-lime, D263 T, Eagle XG)
- Custom options: AOI tuning, ripple flattening, rapid prototypes
Learn more
CTB-002 delivers a moderate “cool-blue” lift when you need to nudge
tungsten or warm-white LEDs toward daylight without the deep output loss of a full
CTB. Transmission peaks near 85 % at 430 nm, stays above 55 % out to ~510 nm, then
decays smoothly—dropping below 40 % near 600 nm and bottoming around 28 % in the
far red. The gentle taper trims excess amber/red while leaving enough green to avoid
cyan shift.
Durable all-oxide coatings survive 1 kW halogen heat or high-power LED engines where
polymer gels fail. KUPO supplies parts in any outline—from 5 mm chips to 450 mm
plates—with thicknesses of 0.21 – 3.8 mm, shipping prototypes in about two weeks.
Typical uses: subtle cooling of stage/architectural rigs, balancing practicals
on film sets, gentle cool-up of studio strobes, museum lighting with low UV, and
machine-vision tasks needing a blue boost without heavy attenuation.
Description
CTB-002 delivers a moderate “cool-blue” lift for times when you need to nudge tungsten or warm-white LEDs toward daylight without the full punch (and light loss) of a heavy blue filter. The coating passes ≈ 85 % around 430 nm, stays above 55 % out to about 510 nm, then decays smoothly: transmission dips below 40 % near 600 nm and bottoms around 28 % in the far-red. That graceful roll-off trims excess amber/red energy while keeping a generous portion of green so colours stay natural, not cyan-shifted.
Key advantages
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Balanced ¼-CTB correction – Lifts CCT by ≈ 800 – 1 000 K, ideal for mixing tungsten with LED or daylight fixtures.
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High blue-region throughput – Maintains fixture punch without the deep attenuation of gel stacks.
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Smooth spectral taper – Avoids abrupt “spikes” that would skew camera colour-matching or introduce green cast.
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Durable all-oxide coating – Withstands sustained heat from 1 kW tungsten halogen or high-power LED engines.
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Custom sizing & substrates – Any shape 5 – 450 mm on Borofloat®, soda-lime, D263 T or Corning Eagle XG, 0.21 – 3.8 mm thick.
Typical applications
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Stage & architectural lighting – Subtly cool house tungsten rigs to blend with daylight LED walls.
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Film & broadcast – Fine-tune warm practicals so they grade cleanly with daylight scenes.
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Photography strobes & modifiers – Achieve gentle cool-up without multiple gel layers that cut output.
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Museum & retail displays – Raise CCT for truer whites while holding UV below conservation limits.
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Machine-vision illumination – Enhance blue-channel contrast when inspecting fluorescent brighteners or surface coatings.
Need a prototype in days or a thousand pieces next month? CTB-002 filters can be coated, cut and shipped to your exact spec—fast.
