CTO-029 is a Color Temperature Filter designed to warm light smoothly and predictably while keeping transmission stable across the visible range. It follows a controlled spectral tilt that gently reduces blue and cyan energy relative to green through red, producing a natural warming shift that works well for lighting and camera white balance. The response is gradual rather than abrupt, helping maintain clean color transitions without harsh artifacts.
Key advantages
Warming color temperature shift – reduces cool blue and cyan content relative to red and amber for a warmer appearance.
Smooth spectral slope – avoids sharp cutoffs that can cause banding, unnatural hues, or channel artifacts.
Healthy long-wavelength throughput – maintains strong red transmission for natural skin tones and warm highlights.
Consistent tuning behavior – predictable response supports repeatability across fixtures and production batches.
Hard-oxide durability – ion-assisted coating options resist heat, humidity, solvents, and repeated cleaning.
Flexible formats (KUPO custom-made optical filters) – round, square, or complex blanks from 5 mm to 450 mm, 0.21–3.8 mm thick, on Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG glass.
Typical applications
Stage and architectural lighting – warm LED or discharge sources toward a tungsten-like feel while keeping output smooth.
Broadcast and studio fixtures – tune correlated color temperature for consistent camera matching in mixed lighting environments.
Film and photography – warm key or fill light for flattering tones and easier white balance control.
Retail and exhibition lighting – enhance warm materials such as wood, textiles, and food displays with a natural look.
Optical systems needing gentle warming – introduce controlled warmth without harsh spectral discontinuities.
Need prototypes fast or production volumes soon? CTO-029 filters can be coated, diced, and shipped to your exact specifications quickly, and because KUPO can custom-make optical filters, we can tune warming strength, substrate, thickness, and angle-of-incidence targets to match your light source and optical stack.