CTO-018 is a Color Temperature Filter designed to add a light, controlled warming shift while preserving smooth tonal transitions and natural rendering. Transmission is higher through the long-wavelength region and lower in the blue side, creating a gentle warm bias rather than a harsh cutoff. This makes CTO-018 useful when you want a subtle move toward a warmer look that still feels clean and consistent on camera.
Key advantages
Light warming shift – nudges correlated color temperature warmer by slightly reducing blue energy relative to red and amber.
Smooth spectral response – avoids sharp transitions that can produce banding, unnatural hues, or channel artifacts.
Strong long-wavelength throughput – preserves reds and ambers for healthier skin tones and warm highlights.
Stable, repeatable tuning – consistent behavior across the visible range supports matching across fixtures and 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 – add gentle tungsten-like warmth to light sources while keeping output smooth.
Broadcast and studio fixtures – fine-tune correlated color temperature to match cameras, sets, or mixed lighting.
Film and photography – warm key or fill lights for flattering tones and consistent white balance.
Retail and exhibition lighting – enhance warm materials such as wood, textiles, and food displays with a natural look.
Optical systems needing slight warming – introduce controlled warmth without harsh spectral discontinuities.
Need prototypes fast or production volumes soon? CTO-018 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.