CTO-001 Color Temperature Orange (Warming) Filter

Full-CTO glass filter: knocks blue to < 20 % below 530 nm, passes > 90 % around 695 nm, pulling 5600 K lamps down to a tungsten look without gel stacks.

Blue block: < 10 % T @ < 425 nm; ~18 % T @ 450 nm
50 % point: ~590 nm (mid-slope transition)
Red passband: > 90 % T @ 677 – 710 nm
CCT shift: –2 000 K (daylight → tungsten)
Construction: Ion-assisted hard-oxide; 5 – 450 mm, 0.21 – 3.8 mm thick
Custom options: Ripple flattening, AOI tuning, rapid prototypes

Learn more

CTO-001 is a full-strength “warm-up” filter that shifts daylight or cool-white LED fixtures down toward a tungsten feel. Transmission leaves deep-blue energy untouched only below 10 % through 425 nm, rises through ~18 % at 450 nm, then climbs gradually—crossing 50 % near 590 nm—and peaks > 90 % around 695 nm before tapering through the far red. The smooth, rising curve trims excess blue so a 3200 K lamp lands near 5600 K or a warm-white LED gains several thousand kelvin without the output loss of stacked gels.

KUPO coats Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG substrates cut to any outline—from 5 mm chips to 450 mm plates—with thicknesses of 0.21 – 3.8 mm, and can ship prototypes in about two weeks.

Typical uses: daylight-matching tungsten on film sets, cooling stage rigs, CTB flash modifiers in reverse (warm-up), museum/retail lighting that needs a cosy ambience without UV damage, and machine-vision setups that benefit from enhanced red-channel contrast.

$88,888.00

Add to Wishlist

Description

CTO-001 is a full-strength “warm-up” filter that shifts daylight or cool-white LED fixtures down toward a tungsten feel. It transmits less than 10 % of deep blue below 425 nm, reaches only ~18 % at 450 nm, then climbs slowly—crossing 50 % near 590 nm—and peaks above 90 % around 695 nm before tapering through the far-red. The smooth, rising curve knocks the excess blue out of 5600 K sources while letting amber-red energy sail through, producing an output that cameras and eyes read close to 3200 K.

Key advantages

Full CTO shift – Drops correlated colour temperature (CCT) by roughly 2 000 K, turning daylight units into tungsten-balanced sources.
Strong blue suppression – < 20 % T below 530 nm eliminates harsh cool cast without needing multiple gel layers.
High red transmission – > 90 % around 677–710 nm preserves brightness and natural skin tones.
Hard, heat-proof oxide stack – Handles 1 kW HMI, LED engines, or xenon follow-spots where polyester gels fail.
Custom formats – Round, square, or free-form 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

Film & broadcast lighting – Warm daylight HMIs or LED panels to blend with tungsten practicals on set.
Stage & architectural rigs – Create cosy amber looks from cool-white house lights without disposable gels.
Photography flash modifiers – Match strobes to incandescent ambience for mixed-light shooting.
Museum & retail displays – Bring LED spotlights down to warmer CCTs that flatter wood, textiles, and artwork.
Machine-vision & inspection – Increase red-channel contrast for detecting heat-printed codes or organic materials.