Rosco 97

Overview

Rosco #97 "Light Grey" is a neutral grey light filter (gel) from the manufacturer Rosco, part of the Roscolux series (also marketed under the Cinegel line). It is a Neutral Density (ND) filter: the filter material uniformly attenuates the amount of light across the visible spectrum, thereby reducing the brightness of a fixture without shifting its color temperature. This allows a lamp to be dimmed without using a dimmer (which would cause a warm shift with incandescent lights) and without altering the color character of the light.

Filters of this type are standard consumables in lighting and grip departments: they are cut from sheets or rolls and inserted into the gel frame of a fixture or into a frame placed in front of a window or light source.

Technical Data

Roscolux filters are manufactured using a tri-extrusion process, where the colored layer is sealed between two thin clear film layers to reduce color migration and increase durability in front of hot lights.

Available Forms

Rosco #97 is available in the standard Roscolux formats:

• Sheet, typically 20" x 24" (approx. 50 x 61 cm)
• Roll, typically 48" x 25' (approx. 1.22 m x 7.62 m)
• Fluorescent tube sleeves (e.g., for T8 tubes)

Set Usage

#97 is used when a fixture is too bright for the exposure but the hue and light character should remain unchanged. Typical applications:

• Intensity balancing of individual fixtures within a setup without altering color temperature via the dimmer
• Dimming practicals or background lights relative to the key light
• Reducing light levels at windows or light sources where a stronger ND is not required

With 50% transmission, #97 attenuates light by one stop. It is the brightest level in the neutral grey series and thus suitable for relatively fine adjustments; for stronger reduction, darker filters from the same series are used (#98 Medium Grey, #99 Dark Grey).