Rosco Cinegel Quarter Blue Lighting Filter 48"x25' Roll

The Rosco Cinegel Quarter Blue (1/4 CTB) is a color correction filter designed for professionals who need precise, subtle adjustments to tungsten lighting. With a mired shift of -30, it raises the color temperature of a standard 3200°K tungsten source to approximately 3500°K — just enough to compensate for voltage drops on dimmed fixtures or to nudge warm light slightly cooler when working in mixed lighting environments. At 74% transmission, it absorbs less than half a stop of light, making it one of the more efficient correction filters to work with.

Supplied as a 48-inch by 25-foot roll, this format gives lighting departments plenty of material to cut custom pieces for a variety of fixtures, from compact fresnels to large softbox frames and window gels. Rosco's Cinegel line has long been an industry standard in film, television, and theatre production, known for consistent color accuracy and reliable performance under the heat of professional instruments. For crews that need a slight cool push without the dramatic shift of a full or half CTB, the Quarter Blue fills that niche precisely.