CTO-16 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: ~59.5 % T (visible range)
- Peak transmittance: ~93.3 % T near 668 nm
- Minimum transmittance: ~21.8 % T near 458 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-16 delivers a +67 Mired shift to move 5600 K light toward 3800 K. Its smooth spectral slope creates a natural warming effect, with about 59.5 % 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-016 is a mild color-temperature-orange conversion filter with its 60 % transmission crossover at 575 nm. Below the crossover, the filter progressively attenuates blue and green wavelengths, dropping to an average of 23 % in the blue band (450-495 nm) while preserving a gentle violet shoulder near 380 nm. Above the crossover, transmission climbs rapidly through the orange region (avg 77 %) and peaks at 93.3 % in the red (668 nm), delivering strong warm-tone throughput. The NIR region (700-800 nm) averages 83.5 %. The overall effect is a subtle warming shift that nudges a daylight-balanced source toward early-evening warmth without heavy colour distortion.
Key Advantages
- 60 % crossover precisely at 575 nm - defines a controlled transition between suppressed cool tones and transmitted warm tones.
- Peak transmission of 93.3 % at 668 nm - maintains high red-channel brightness, keeping lighting output efficient.
- Gentle blue suppression (avg 23 % at 450-495 nm) - reduces cool-tone energy without eliminating it, preserving a natural appearance.
- Hard-oxide durability - ion-assisted coating withstands high-intensity lamp heat, humidity, and repeated 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 - adds a subtle golden warmth to daylight-balanced LED and discharge fixtures for sunrise or early-evening scenes.
- Architectural and hospitality lighting - shifts cool-white sources toward a warmer correlated colour temperature (CCT) for inviting interior atmospheres.
- Film and broadcast colour correction - gently warms on-camera lighting to blend daylight with tungsten sources without full CTO conversion.
- Machine vision colour filtering - preferentially passes orange-red illumination for contrast enhancement against blue or green backgrounds.
- Phototherapy and wellness lighting - shapes the spectral output of broadband sources to emphasise warm tones associated with circadian comfort.
Need prototypes in days or production volumes next quarter? CTO-016 filters can be coated, diced, and shipped to your exact specifications.
FAQ
CTO-16 FAQ
What is CTO-16 and what is it used for?
CTO-16 is a Color Temperature Orange Filter - Mild Warm Shift (T60 % = 575 nm). CTO-16 is a mild color-temperature-orange conversion filter with its 60 % transmission crossover at 575 nm. Below the crossover, the filter progressively attenuates blue and green wavelengths, dropping to an average of 23 % in the blue band (450-495 nm) while preserving a gentle violet shoulder near 380 nm. Common uses include Stage and theatrical lighting, Architectural and hospitality lighting, Film and broadcast colour correction, and Machine vision colour filtering.
What are the key optical specs of CTO-16?
Key published specs for CTO-16 include Colour shift direction: Warming (5600 K → 3800 K); Mired shift: +67 Mired; Correction strength: 1/2 CTO; Average transmittance: ~59.5 % T (visible range); Peak transmittance: ~93.3 % T near 668 nm.
What applications is CTO-16 best suited for?
CTO-16 is commonly used for Stage and theatrical lighting, Architectural and hospitality lighting, Film and broadcast colour correction, and Machine vision colour filtering. Stage and theatrical lighting - adds a subtle golden warmth to daylight-balanced LED and discharge fixtures for sunrise or early-evening scenes.
Can CTO-16 be customized for size, substrate, or coating requirements?
KUPO lists the construction for CTO-16 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-16?
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
