CTO-038 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: ~58.3 % T (visible range)
- Peak transmittance: ~95.2 % T near 701 nm
- Minimum transmittance: ~13.2 % T near 484 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-038 delivers a +67 Mired shift to move 5600 K light toward 3800 K. Its smooth spectral slope creates a natural warming effect, with about 58.3 % 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-038 provides a moderate colour-temperature shift with its 50 % crossover at 556 nm and a broad warm plateau. Transmission exceeds 85 % from 582-750 nm, peaking at 95.2 % at 701 nm. The yellow-to-red bands carry strong energy: yellow at 82.3 %, orange at 92.2 %, and red at 90.0 %. Blue is suppressed to 14.1 %. NIR averages 83.7 % with a gentle roll-off at the long-wavelength end. The overall shape produces a rich, even warm output across the yellow-through-red spectrum.
Key Advantages
- 50 % crossover at 556 nm with broad warm plateau - delivers even warm-tone coverage from yellow through deep red.
- Peak of 95.2 % at 701 nm - places maximum efficiency at the red-NIR boundary for high output.
- Strong blue suppression (avg 14.1 %) - ensures the warm character is dominant with minimal cool contamination.
- 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 - delivers a rich, warm wash with even spectral coverage across the warm bands for natural-looking scene lighting.
- Film and broadcast production - provides standard CTO colour correction with a smooth, film-friendly spectral profile.
- Retail and hospitality lighting - converts cool-white fixtures to warm ambiance while maintaining high colour rendering in the warm spectrum.
- Machine vision warm-band imaging - emphasises orange-red illumination for contrast enhancement in food inspection and material sorting.
- Photographic filtration - delivers a moderate warming effect with high peak transmission for minimal exposure compensation.
Need prototypes in days or production volumes next quarter? CTO-038 filters can be coated, diced, and shipped to your exact specifications.
FAQ
CTO-038 FAQ
What is CTO-038 and what is it used for?
CTO-038 is a Color Temperature Orange Filter - Moderate CTO with Warm Plateau (T50 % = 555 nm). CTO-038 provides a moderate colour-temperature shift with its 50 % crossover at 556 nm and a broad warm plateau. Transmission exceeds 85 % from 582-750 nm, peaking at 95.2 % at 701 nm. Common uses include Stage and event lighting, Film and broadcast production, Retail and hospitality lighting, and Machine vision warm-band imaging.
What are the key optical specs of CTO-038?
Key published specs for CTO-038 include Colour shift direction: Warming (5600 K → 3800 K); Mired shift: +67 Mired; Correction strength: 1/2 CTO; Average transmittance: ~58.3 % T (visible range); Peak transmittance: ~95.2 % T near 701 nm.
What applications is CTO-038 best suited for?
CTO-038 is commonly used for Stage and event lighting, Film and broadcast production, Retail and hospitality lighting, and Machine vision warm-band imaging. Stage and event lighting - delivers a rich, warm wash with even spectral coverage across the warm bands for natural-looking scene lighting.
Can CTO-038 be customized for size, substrate, or coating requirements?
KUPO lists the construction for CTO-038 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-038?
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
