CTO-046 Color Temperature Orange (Warming) Filter
1/2 CTO colour-conversion filter shifting 5600 K toward 3800 K for seamless mixed-lighting balance in broadcast, film, and architectural applications.
- Colour shift direction: Warming (5600 K → 3800 K)
- Mired shift: +67 Mired
- Correction strength: 1/2 CTO
- Average transmittance: ~58.9 % T (visible range)
- Peak transmittance: ~94.9 % T near 758 nm
- Minimum transmittance: ~8.8 % T near 442 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-046 delivers a +67 Mired shift to move 5600 K light toward 3800 K. Its smooth spectral slope creates a natural warming effect, with about 58.9 % average visible transmittance and approximately 0.7 stops of light loss.
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
Moderate warming when daylight and tungsten need to blend, especially for interview lighting, event rigs, and warmer skin tones.
Description
CTO-046 sits at the three-quarter CTO mark with its 50 % crossover at 576 nm. Blue wavelengths are suppressed to 17.9 %, green to 40 %, while the warm bands deliver strong throughput: orange at 74.2 %, red at 91.3 %, and NIR at 92.3 %, peaking at 94.9 % at 758 nm. The smooth, steadily rising profile from blue through NIR produces a clean, predictable warm shift that sits between half and full CTO in strength.
Key Advantages
- 50 % crossover at 576 nm (three-quarter CTO position) - provides a warm shift stronger than half CTO but short of full conversion, offering precise intermediate control.
- High NIR peak of 94.9 % at 758 nm - maintains excellent long-wavelength efficiency.
- Smooth, predictable spectral curve - produces a clean warm shift without spectral artefacts or secondary features.
- Hard-oxide durability - ion-assisted coating withstands high lamp 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 event lighting - provides a three-quarter CTO for precise colour-temperature control when half CTO is too subtle and full CTO is too strong.
- Film and broadcast fine-tuning - enables accurate intermediate colour-temperature matching between daylight and tungsten sources.
- Architectural lighting design - delivers a warm shift calibrated for environments that need more warmth than standard half CTO.
- Photography and cinematography - offers an intermediate warming effect for golden-hour simulation and warm-tone portraiture.
- LED fixture colour customisation - tunes the output of cool LED modules to a specific intermediate CCT without over-converting.
Need prototypes in days or production volumes next quarter? CTO-046 filters can be coated, diced, and shipped to your exact specifications.
FAQ
CTO-046 FAQ
What is CTO-046 and what is it used for?
CTO-046 is a Color Temperature Orange Filter - Three-Quarter CTO (T50 % = 576 nm). CTO-046 sits at the three-quarter CTO mark with its 50 % crossover at 576 nm. Blue wavelengths are suppressed to 17.9 %, green to 40 %, while the warm bands deliver strong throughput: orange at 74.2 %, red at 91.3 %, and NIR at 92.3 %, peaking at 94.9 % at 758 nm. Common uses include Stage and event lighting, Film and broadcast fine-tuning, Architectural lighting design, and Photography and cinematography.
What are the key optical specs of CTO-046?
Key published specs for CTO-046 include Colour shift direction: Warming (5600 K → 3800 K); Mired shift: +67 Mired; Correction strength: 1/2 CTO; Average transmittance: ~58.9 % T (visible range); Peak transmittance: ~94.9 % T near 758 nm.
What applications is CTO-046 best suited for?
CTO-046 is commonly used for Stage and event lighting, Film and broadcast fine-tuning, Architectural lighting design, and Photography and cinematography. Stage and event lighting - provides a three-quarter CTO for precise colour-temperature control when half CTO is too subtle and full CTO is too strong.
Can CTO-046 be customized for size, substrate, or coating requirements?
KUPO lists the construction for CTO-046 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-046?
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
