Diffusion fabric in asymmetrical frame reducing half the light by 0.3 stops, creating soft transitions for portrait work.
Technical Details
Standard half single scrims are manufactured in frame sizes from 12"×18" to 48"×48", with 18"×24" and 24"×36" being the most commonly used. The scrim fabric is made of white cotton or polyester with a mesh size of 0.8-1.2mm and weighs between 80-120g/m². The asymmetrical diffusion is applied either vertically or horizontally, with the transition between the covered and open area creating a soft gradient approximately 2-3cm wide. Double half scrims (0.6 f-stops) and silk half variants are also available for stronger diffusion.
History & Development
Scrims originated in Hollywood in the 1920s as a cost-effective alternative to glass filters. Mole-Richardson developed the first standardized scrim frames for their Fresnel lights in 1934. The half single variant became established in the 1950s when cinematographers like James Wong Howe required precise light transitions for portraits. Matthews Studio Equipment standardized the currently common frame sizes and fabric specifications in 1967. Modern LED panels have increased the demand for scrims again, as their hard light often requires diffusion.
Practical Use in Film
Half single scrims create asymmetrical lighting for portraits where one side of the face is to be lit more softly. Gordon Willis used them extensively in "The Godfather" (1972) for the characteristic shadow-light transitions. Typical workflow: positioning between the light source and the subject at a distance of 0.5-2m, with the gradient becoming softer or harder depending on the distance. In exterior shots, they compensate for different exposures between the sky and the foreground. The disadvantage lies in the fixed 0.3-stop reduction without stepless adjustment.
Comparison & Alternatives
Unlike full single scrims, which reduce the entire light uniformly, half single scrims create deliberate brightness differences. Graduated ND filters on the lens offer similar effects but are less flexibly positionable. Modern LED panels with dimmable segments can digitally simulate half scrim effects but do not achieve the natural gradation of the fabric. The advantage of classic scrims: they work with any light source and cost under 50 Euros each.