CTO-035 Color Temperature Orange (Warming) Filter
3/4 CTO colour-conversion filter shifting 5600 K toward 3400 K for seamless mixed-lighting balance in broadcast, film, and architectural applications.
- Colour shift direction: Warming (5600 K → 3400 K)
- Mired shift: +100 Mired
- Correction strength: 3/4 CTO
- Average transmittance: ~51.4 % T (visible range)
- Peak transmittance: ~96.0 % T near 708 nm
- Minimum transmittance: ~0.5 % T near 397 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-035 delivers a +100 Mired shift to move 5600 K light toward 3400 K. Its smooth spectral slope creates a natural warming effect, with about 51.4 % average visible transmittance and a low amount of light loss.
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
Strong but not full warming when you want a natural blend between daylight and tungsten sources.
Description
CTO-035 features the sharpest edge profile of any CTO in the series: transmission drops below 5 % from 380-427 nm, then rises steeply through a precisely defined transition to reach 50 % at 600 nm and 85 % by 625 nm. Red transmission averages 92.6 % and NIR averages 95.3 %, peaking at 96.0 % at 708 nm. The sharp UV-blue blocking and steep cut-on produce an exceptionally clean orange longpass with no residual violet shoulder or blue leakage.
Key Advantages
- Sharp cut-on with T < 5 % at 380-427 nm - provides complete UV-blue blocking for a clean orange-red output with no short-wavelength leakage.
- 50 % crossover at 600 nm with T > 85 % by 625 nm - defines a steep, well-controlled transition into the warm passband.
- Peak of 96.0 % at 708 nm with NIR avg 95.3 % - delivers outstanding long-wavelength efficiency.
- 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 architectural lighting - delivers a pristine orange-red output with zero blue-violet leakage for colour-critical warm-wash applications.
- Film and broadcast colour correction - provides a clean orange longpass for precise daylight-to-tungsten conversion without secondary colour artefacts.
- Machine vision and optical sensing - functions as a sharp-edge orange longpass for wavelength-selective imaging and spectral sorting.
- Scientific instrumentation - the well-defined cut-on at 600 nm makes this filter suitable as a reference longpass for spectrophotometer calibration.
- Solar energy and photovoltaic testing - selects the orange-to-NIR portion of the solar spectrum for characterising silicon cell response above 600 nm.
Need prototypes in days or production volumes next quarter? CTO-035 filters can be coated, diced, and shipped to your exact specifications.
FAQ
CTO-035 FAQ
What is CTO-035 and what is it used for?
CTO-035 is a Color Temperature Orange Filter - Sharp-Edge Orange (T50 % = 600 nm). CTO-035 features the sharpest edge profile of any CTO in the series: transmission drops below 5 % from 380-427 nm, then rises steeply through a precisely defined transition to reach 50 % at 600 nm and 85 % by 625 nm. Red transmission averages 92.6 % and NIR averages 95.3 %, peaking at 96.0 % at 708 nm. Common uses include Stage and architectural lighting, Film and broadcast colour correction, Machine vision and optical sensing, and Scientific instrumentation.
What are the key optical specs of CTO-035?
Key published specs for CTO-035 include Colour shift direction: Warming (5600 K → 3400 K); Mired shift: +100 Mired; Correction strength: 3/4 CTO; Average transmittance: ~51.4 % T (visible range); Peak transmittance: ~96.0 % T near 708 nm.
What applications is CTO-035 best suited for?
CTO-035 is commonly used for Stage and architectural lighting, Film and broadcast colour correction, Machine vision and optical sensing, and Scientific instrumentation. Stage and architectural lighting - delivers a pristine orange-red output with zero blue-violet leakage for colour-critical warm-wash applications.
Can CTO-035 be customized for size, substrate, or coating requirements?
KUPO lists the construction for CTO-035 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-035?
The ion-assisted hard-oxide coating is built for repeated handling, heat, and cleaning.
