WHAT DIFFUSION DOES
On an overcast day, water vapor in the cloud cover alters the harsh directional quality of sunlight by causing it to be spread out or dispersed. The resulting light seems to be coming from the entire sky, producing an illumination that is softly diffuse. Shadows are faint or undefined. Contrast is lowered.
Rosco diffusion material acts in a similar fashion. When placed in the beam path of a lighting fixture, diffusion material modifies the harsh quality of the light by spreading or dispersing the beam. This softens the quality of the illumination by increasing the apparent beam size and thereby altering the beam's "shadow casting properties".
The most important difference between atmospheric diffusion and Rosco's version is that the Rosco diffusion materials can be utilized to produce controllable and predictable results at any time.
USE AND PLACEMENT OF DIFFUSION MATERIAL
Diffusion material can be placed at the source in a gel holder, clipped to barn doors or positioned in front of a fixture in a frame. Each position produces a slightly different effect.
Large diffusion panels can turn multiple lighting fixtures into a single source of soft, low contrast illumination. As overheads, diffusion can be placed above sets to deliver a soft, overcast look or used outdoors to diffuse harsh sunlight. Sets can even be "tented or completely surrounded with diffusion to produce an extremely soft, shadowless quality that is particularly useful for product photography of specular objects like glassware, jewelry and automobiles.
Diffusion Types - "Tough"
The following diffusion groups are designated "Tough". This indicates that the base material is a heat stable polyester that can be used with most high-temperature lighting fixtures.
Tough Lux - Set Shop Original Brand
Set Shop Brand Diffusion Material Tough Lux is available in 60” wide, 4 mil thick and 48” wide, 3 mil thick, 15-foot long rolls. We also offer it at a per yard price. Our diffusion material is a polyester based film with properties consisting of being stable and heat resistant. Noted photographer and author, Steve Sint, strongly stresses that you leave enough space for airflow between the light and the Tough Lux diffusion material to lessen (but not totally eliminate!) the possibility of a fire hazard. While the possibility of a fire hazard is less serious when using electronic flash without modeling lamps, quartz modeling lamps and quartz video lights generate enough heat to demand both care and adequate airflow when they are being used with Tough Lux in this manner.
Polyester materials will melt at approximately 356 degrees Fahrenheit. For comparison, ordinary paper bursts into flames at 451 degrees Fahrenheit.
Set Shop Brand Diffusion Material Tough Lux is printable with anti static properties. This material has excellent toner adhesion and is well suited for multi color screen-printing jobs. This is compatible with most laser printers and copiers.
TOUGH ROLUX - Rosco Original Brand
The original dense diffuser. Wide beam spread creates an even field of soft, shadowless light.
Set Shop Brand Diffusion Material Tough Lux and Tough Rolux Rosco Original Brand produce an identical diffused effect.