CTB-013 Color Correction Filters
CTB-013 is a blue-balancing broadband filter with pronounced mid-band trim and strong red recovery: T starts ~82–84 % at 380–400 nm, peaks ~90–92 % at 450–480 nm, dips to ~50–52 % near 590–620 nm, then rises to ~90–93 % by 760–780 nm—delivering a clear cool shift that preserves deep-red content (~0.3 OD at the trough).
- Function: CTB broadband filter with mid-band trim & strong red recovery
- Blue weighting: Lift to ~90–92 % T at 450–480 nm (from ~82–84 % @ 380–400 nm)
- Mid-band moderation: Smooth fall; minimum ~50–52 % T around 590–620 nm
- Deep-red recovery: Rapid rise to ~90–93 % T by 760–780 nm (preserves R9/skin tones)
- Curve quality: Low-ripple, no notches; ~0.3 OD attenuation at the trough
- Construction & format: Durable coating on Borofloat®, Eagle XG, D263 T, or soda-lime • 5–450 mm • 0.21–3.8 mm • options: rear-AR & slight wedge
Learn more
CTB-013 pushes warm sources toward daylight by lifting 450–480 nm while moderating yellow/amber through ~540–640 nm. Unlike harsher CTB profiles, it recovers strongly in the long red to maintain deep-red fidelity (e.g., R9/skin tones) while keeping the overall look cool and neutral.
Typical applications • Lighting colour correction (daylight-leaning with red fidelity) • Cameras & cinema (reduce blue-channel gain; keep skin-tone reds alive) • Architectural/display lighting (crisp whites) • Machine vision/inspection (boost blue features without losing long-red cues) • Projectors & light engines (predictable spectral shaping).
Need test chips tomorrow or thousands next quarter? CTB-013 filters are coated and cut-to-size (including dicing) to your exact spec—fast.
Description
CTB-013 is a blue-balancing (CTB) broadband filter with a pronounced mid-band trim and strong red recovery. Transmission starts around ~82–84% near 380–400 nm, climbs to ~90–92% at ~450–480 nm, dips through green/yellow to a minimum of ~50–52% around ~590–620 nm, then rises steadily to ~90–93% by ~760–780 nm. The result is a clear cool-tone correction that preserves deep-red content (mid-band attenuation ≈0.3 OD at the trough).
Key advantages
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Blue-weighted transmission — lifts 450–480 nm to push warm sources toward daylight.
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Mid-band moderation — smooth falloff through ~540–640 nm reduces yellow/amber without harsh notches.
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Deep-red recovery — rapid rise beyond ~650 nm maintains R9/skin-tone reds while staying overall cool.
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Smooth, low-ripple curve — predictable colourimetry; no narrow notches or banding.
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Built to last — durable optical coating for stage, field, and lab use.
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Custom formats — Borofloat®, Eagle XG, or D263 T (0.21–3.8 mm) for high-temp duty to ~450 °C; soda-lime for ≤150 °C. Sizes 5–450 mm; optional rear-surface AR and slight wedge to suppress ghosts.
Typical applications
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Lighting colour correction — cool tungsten/halogen or warm LED toward ~5600 K daylight while retaining deep-red fidelity.
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Cameras & cinema — pre-filter to reduce blue-channel gain and keep skin-tone reds alive.
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Architectural & display lighting — crisp whites in retail, museums, and exhibits.
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Machine vision & inspection — enhance blue-weighted contrast without sacrificing long-red features.
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Projectors & light engines — spectral shaping with manageable brightness trade-off.
Need test chips tomorrow or thousands next quarter? CTB-013 filters are coated and cut-to-size (including dicing) to your exact spec—fast.
