CTO-029 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: ~56.4 % T (visible range)
- Peak transmittance: ~96.2 % T near 629 nm
- Minimum transmittance: ~14.7 % T near 455 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-029 delivers a +67 Mired shift to move 5600 K light toward 3800 K. Its smooth spectral slope creates a natural warming effect, with about 56.4 % 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-029 stands apart from the rest of the CTO series with its distinctive bandpass-shaped profile. Rather than a simple longpass, it features a broad transmission peak centred on the orange-red region, with its 70 % transmission crossover at 595 nm. Transmission rises sharply through the yellow-orange transition, peaks at 96.2 % at 629 nm, holds above 85 % from 609 nm to 668 nm, then rolls off in the NIR, dropping to 50.7 % at 800 nm. Blue wavelengths average 29.6 %. The result is a focused warm-band filter that concentrates energy in the orange-red without passing excess NIR radiation.
Key Advantages
- Bandpass-shaped profile peaking at 96.2 % at 629 nm - concentrates output in the orange-red band for a vivid, saturated warm tone.
- 70 % crossover at 593 nm - defines a steep transition into the warm passband.
- NIR roll-off (800 nm at 50.7 %) - reduces infrared heat load compared to standard longpass CTOs, protecting heat-sensitive elements.
- Hard-oxide durability - ion-assisted coating survives 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 theatrical lighting - creates a focused, saturated orange-amber wash without excess NIR heat that could damage gels or set materials.
- Film colour effects - delivers a concentrated warm band for stylised on-camera colour without the colour shift caused by rising NIR transmission.
- Heat-managed projection and display - provides warm-tone filtering while limiting infrared throughput, reducing thermal load on downstream optics and screens.
- Machine vision orange-band isolation - passes a well-defined orange-red band for fruit sorting, chemical detection, or colour-coded label reading.
- Photobiology and circadian research - isolates the orange-red spectral region for studying melanopsin response and melatonin suppression thresholds.
Need prototypes in days or production volumes next quarter? CTO-029 filters can be coated, diced, and shipped to your exact specifications.
FAQ
CTO-029 FAQ
What is CTO-029 and what is it used for?
CTO-029 is a Color Temperature Orange Filter - Bandpass-Shaped Warm Filter (T70 % = 593 nm). CTO-029 stands apart from the rest of the CTO series with its distinctive bandpass-shaped profile. Rather than a simple longpass, it features a broad transmission peak centred on the orange-red region, with its 70 % transmission crossover at 595 nm. Common uses include Stage and theatrical lighting, Film colour effects, Heat-managed projection and display, and Machine vision orange-band isolation.
What are the key optical specs of CTO-029?
Key published specs for CTO-029 include Colour shift direction: Warming (5600 K → 3800 K); Mired shift: +67 Mired; Correction strength: 1/2 CTO; Average transmittance: ~56.4 % T (visible range); Peak transmittance: ~96.2 % T near 629 nm.
What applications is CTO-029 best suited for?
CTO-029 is commonly used for Stage and theatrical lighting, Film colour effects, Heat-managed projection and display, and Machine vision orange-band isolation. Stage and theatrical lighting - creates a focused, saturated orange-amber wash without excess NIR heat that could damage gels or set materials.
Can CTO-029 be customized for size, substrate, or coating requirements?
KUPO lists the construction for CTO-029 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-029?
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
