CTO-056 Color Temperature Orange (Warming) Filter
1/4 CTO colour-conversion filter shifting 5600 K toward 4500 K for seamless mixed-lighting balance in broadcast, film, and architectural applications.
- Colour shift direction: Warming (5600 K → 4500 K)
- Mired shift: +35 Mired
- Correction strength: 1/4 CTO
- Average transmittance: ~62.2 % T (visible range)
- Peak transmittance: ~95.8 % T near 626 nm
- Minimum transmittance: ~8.4 % T near 437 nm
- Construction: Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick
- Custom options: Intermediate Mired shifts, combined CTO+diffusion, custom sizes, rapid prototypes
Learn more
CTO-056 delivers a +35 Mired shift to move 5600 K light toward 4500 K. Its smooth spectral slope creates a natural warming effect, with about 62.2 % average visible transmittance and approximately 0.3 stops of light loss.
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
Light warming for white-balance fine-tuning, subtle skin-tone warmth, and gentle golden-hour style looks.
Description
CTO-056 features an unusually broad transmission profile with T > 85 % extending from 380 nm all the way to 800 nm - by far the widest high-transmission range in the CTO series. Its 50 % crossover sits at 583 nm, but the profile maintains significant violet-band throughput (380 nm at 90.4 %). The filter selectively suppresses blue and green (avg 28.7 % and 32.2 %) while keeping violet, orange, red, and NIR strongly transmitted. Red averages 92.6 % with a peak of 95.8 % at 626 nm. The result is a broadband warm filter with distinctive violet preservation.
Key Advantages
- Ultrawide high-transmission band (T > 85 % at both 380 nm and 800 nm) - provides the broadest passband of any CTO in the series with selective internal suppression.
- Selective blue-green suppression - removes the 450-570 nm band while preserving violet and warm wavelengths for a unique spectral signature.
- Peak of 95.8 % at 626 nm - centres maximum output in the orange-red for strong warm character.
- Hard-oxide durability - ion-assisted coating withstands heat, humidity, solvents, and cleaning.
- Custom formats available - round, square, or free-form blanks from 5 mm to 450 mm, thickness 0.21-3.8 mm, on Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG substrates.
Typical Applications
- Stage and theatrical lighting - creates a warm wash with a violet undertone for rich, complex warm-scene lighting.
- Film and photography colour effects - adds warmth while preserving violet tones for a distinctive cinematic look that differs from standard CTO.
- Architectural and accent lighting - delivers warm illumination with a hint of violet for contemporary interior design aesthetics.
- Display and projection colour shaping - selectively suppresses the blue-green portion of LED spectra while preserving overall spectral breadth.
- Scientific spectral shaping - provides a unique blue-green notch within a broad passband for optical research and spectral studies.
Need prototypes in days or production volumes next quarter? CTO-056 filters can be coated, diced, and shipped to your exact specifications.
FAQ
CTO-056 FAQ
What is CTO-056 and what is it used for?
CTO-056 is a Color Temperature Orange Filter - Broadband Warm Transmission (T50% = 583 nm). CTO-056 is a broadband warm transmission filter with its 50 % crossover at 583 nm. Unlike sharper CTOs, this filter maintains a broad warm passband that provides smooth, gradual warming without a hard cut. Violet averages 7.4 % and blue 8.5 %, while transmission climbs through green (27.6 %), yellow (64.0 %), orange (83.8 %), red (93.1 %), and peaks at 95.8 % in the NIR. Common uses include Stage and event lighting warm fills, Film and broadcast warm colour correction, Architectural ambient warm lighting, and Photography warm filtration.
What are the key optical specs of CTO-056?
Key published specs for CTO-056 include Colour shift direction: Warming (5600 K → 3400 K); Mired shift: +100 Mired; Correction strength: 3/4 CTO; Average transmittance: ~47.4 % T (visible range); Peak transmittance: ~95.8 % T near NIR.
What applications is CTO-056 best suited for?
CTO-056 is commonly used for Stage and event lighting warm fills, Film and broadcast warm colour correction, Architectural ambient warm lighting, and Photography warm filtration. Stage and event lighting - provides a reliable three-quarter CTO correction for consistent warm fills across multiple fixtures.
Can CTO-056 be customized for size, substrate, or coating requirements?
KUPO lists the construction for CTO-056 as Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick. Published custom options include Intermediate Mired shifts, combined CTO+diffusion, custom sizes, rapid prototypes. Custom formats available - round, square, or free-form blanks from 5 mm to 450 mm, thickness 0.21-3.8 mm, on Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG substrates.
What should I know about angle of incidence and durability for CTO-056?
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
