The Workhorse of Diffusion Fabrics 💪
In the toolkit of a motion picture grip, Grid-cloth is one of the most essential and versatile materials for light modification. Its primary function is diffusion: to take a ‘hard’ light source (one that creates sharp, defined shadows, like the sun or a Fresnel lamp) and transform it into a larger, softer source that creates more pleasing, gentle shadows. This is achieved by stretching the fabric taut in a large metal frame and placing it in the path of the light.
Properties and Strengths
Grid-cloth is prized for its specific characteristics:
- The Grid Pattern: Its most obvious feature is the grid of heavier threads woven into the fabric in a square pattern. This is a rip-stop design that gives the material exceptional strength and prevents small punctures from turning into large tears, even under high wind conditions on exterior shoots.
- Diffusion Quality: It provides a medium-heavy diffusion, effectively softening a light source while still allowing for a good amount of light transmission. It creates a beautiful, smooth field of light.
- Standardized Densities: To provide cinematographers with precise control, Grid-cloth is manufactured in several standard densities:
- Full Grid Cloth: Offers the most diffusion.
- Light Grid Cloth (or Half Grid): A medium, less dense version.
- Quarter Grid Cloth: A very light diffusion for just taking the ‘edge’ off a hard source.
Grid-cloth: On-Set Applications
The durability of Grid-cloth makes it the go-to choice for large-scale diffusion. Grip crews will stretch it on frames of all sizes, from a small 4x4’ frame to massive 20x20’ frames on exterior locations.
- Softening Sunlight: A common use is to fly a large frame of Grid-cloth over actors on a sunny day to soften the harsh overhead sun, creating a more flattering ‘open shade’ look.
- Creating Soft Boxes: It’s used as the front screen on large soft boxes (often called ‘rags’) built around powerful lights.
- Book Lights: It is often used as the diffusion layer in a ‘book light’ setup, where a light is bounced off a white surface and then passed through the Grid-cloth for an extra layer of softness.