CTB-200 Color Correction Filter
Full-strength CTB glass filter: keeps 390–495 nm > 90 % T, slashes green–amber to ~10 % around 590 nm, and nudges tungsten up to daylight CCT without gel stacks.
- Blue boost: 390 – 495 nm, > 90 % T
- Mid-band dip: ~10 % T @ 590 nm
- Far-red: 15 – 25 % T @ 700 – 750 nm
- CCT shift: 3200 K → ≈ 5600 K (full CTB)
- Construction: Ion-assisted hard-oxide; 5 – 450 mm, 0.21 – 3.8 mm thick
- Custom options: AOI tuning, ripple flattening, rapid prototypes
Learn more
CTB-200 leaves virtually all deep-blue and violet energy untouched—
maintaining > 90 % transmission from ~390 nm to 495 nm—then cuts aggressively
through the green-amber band, bottoming near 10 % around 590 nm. Red energy reaches
only 15–25 % in the far-red before dropping again past 760 nm. A 3200 K lamp shifts
to roughly 5600 K; warm-white LEDs jump several thousand kelvin without the heavy
losses of plastic gels.
KUPO coats Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG substrates in
any outline—from 5 mm chips to 450 mm plates—at thicknesses of 0.21 – 3.8 mm.
Prototypes ship in about two weeks.
Typical uses: daylight-matching tungsten on film sets, cooling stage rigs,
CTB flash modifiers, high-CCT museum lighting, and blue-channel machine-vision where
polymer gels can’t take the heat.
Description
CTB-200 is our full-strength “daylight blue” correction filter. It leaves virtually all deep-blue and violet energy untouched—maintaining > 90 % transmission from about 390 nm to 495 nm—then cuts aggressively through the green–amber band, bottoming near 10 % around 590 nm. Transmission rises only slightly (15–25 %) through the far-red before climbing again beyond 740 nm. Used on a 3200 K tungsten lamp, CTB-200 pushes the output close to 5600 K daylight; on warm-white LEDs it lifts CCT several thousand kelvin without the heavy losses that stacked plastic gels impose.
Key advantages
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Full CTB shift – Boosts blue content enough to convert 3200 K tungsten to ~5600 K daylight.
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High blue throughput – > 90 % transmission between 390–495 nm keeps luminance high where correction is most needed.
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Strong mid-band attenuation – Green–amber suppression pulls the spectral balance toward a crisp, camera-friendly white.
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Heat-tough oxide coating – Survives 1 kW halogen and high-power COB LEDs without warping, bubbling, or color shift.
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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.
Typical applications
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Film & broadcast lighting – Match tungsten practicals to daylight HMIs or sunlit exteriors in a single pass.
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Stage & architectural rigs – Cool whole banks of PARs or ellipsoidals without disposable gels.
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Photography flash modifiers – Shift studio strobes for mixed-light sets while retaining punch.
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Museum & retail displays – Raise colour temperature for truer whites yet block most damaging UV.
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Machine-vision & inspection – Enhance blue-channel contrast for fluorescent optical brighteners or tracer dyes.
Need prototypes in a week or production lots next quarter? CTB-200 filters can be coated, diced, and delivered to your exact specification—fast.
