CTO-007 Color Correction Filter
¾-CTO glass filter: trims blue below 440 nm, peaks ≈ 90 % at 625 nm, and drops a daylight source ~1 800 K toward tungsten without big lumen loss.
- Blue block: < 10 % T @ < 440 nm • 20 % T @ 490 nm
- Mid slope: 40 % T @ 530 nm (smooth transition)
- Red plateau: 80 – 90 % T @ 600 – 700 nm (peak ≈ 90 % T @ 625 nm)
- CCT shift: −1 800 K (≈ ¾-CTO)
- Construction: Ion-assisted hard-oxide; 5 – 450 mm, 0.21 – 3.8 mm thick
- Custom options: AOI tuning, ripple flattening, rapid prototypes
Learn more
CTO-007 applies a strong amber tilt—about a ¾-CTO step—ideal for nudging daylight
fixtures toward classic tungsten warmth without the heavy output loss of full CTO gels.
Transmission sits below 10 % through the violet–blue band under 440 nm, rises to ~20 % at
490 nm, crosses 40 % by ~530 nm, and peaks just shy of 90 % around 625 nm before tapering
through the deep red. The balanced ramp removes sufficient blue/green to shift a 5600 K
source down to roughly 3600 – 3800 K, all while preserving brightness and skin-tone
accuracy.
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—in thicknesses of 0.21 – 3.8 mm. Prototypes
ship in about two weeks.
Typical uses: balancing daylight heads to tungsten fills on set, warming cool LED
house lights, gentle flash modifiers, cosy museum/retail lighting, and machine-vision
tasks needing a red-channel boost without large lumen loss.
Description
CTO-007 applies a strong amber tilt—roughly a ¾-CTO step—for cooling-daylight fixtures that need to land closer to classic tungsten warmth. Transmission is under 10 % through the violet–blue band below about 440 nm, rises to ~20 % at 490 nm, crosses 40 % near 530 nm, and peaks just shy of 90 % around 625 nm before tapering toward the deep red. The smooth ramp removes enough blue/green to shift a 5600 K source down to roughly 3600 – 3800 K, providing cosy ambience while keeping plenty of output.
Key advantages
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Robust ¾-CTO shift – Drops CCT by roughly 1 800 K, ideal for marrying daylight heads to tungsten fills without a full CTO hit on brightness.
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High red throughput – ≥ 80 % from 600 – 700 nm preserves luminous punch and natural skin tones.
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Progressive blue cut – No sharp notches, so cameras see a neutral spectrum without unwanted green spikes.
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Heat-resistant oxide coating – Handles high-power LEDs, HMIs, and follow-spots where plastic gels degrade.
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Customisable blanks – Round, square, or free-form pieces 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
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Film & broadcast lighting – Warm daylight panels or HMIs so they cut seamlessly with tungsten practicals.
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Stage & architectural rigs – Turn cool house LEDs into inviting amber washes without disposable gels.
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Photography modifiers – Shift flash packs toward incandescent warmth for mixed-light shoots.
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Museum & retail displays – Add warmth to LED spotlights while keeping UV extremely low.
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Machine-vision illumination – Boost red-channel contrast when inspecting organic or heat-printed materials.
Need prototypes in days or production lots next quarter? CTO-007 filters can be coated, cut, and shipped to your exact spec—fast.
