Rosco 129

Overview

Rosco 129 is designated "Heavy Frost" and is a diffusion filter (colloquially "gel" or film) from the manufacturer Rosco. It is not a color or color correction filter, but a pure diffusion material that transforms hard, direct light into a soft, widely scattered light source.

According to the manufacturer, 129 "is a strong diffusion that virtually eliminates all shadows." Within Rosco's Frost family, Heavy Frost is therefore among the stronger diffusion levels – significantly more powerful than lighter levels like Light Frost or Tough Frost.

The number 129 appears in two Rosco product lines: in the American line Roscolux #129 and in the European line E-Colour+ #129. Since E-Colour+ follows the European numbering system, the 129 also corresponds to the number LEE 129 "Heavy Frost".

Technical Data

As is common with diffusion filters, a significant light loss is to be expected; depending on the source, the loss is stated as several f-stops. Exact values for transmission and f-stop loss should be taken from the current data sheet from Rosco or LEE before use.

Use on Set

Heavy Frost is stretched in front of a spotlight, frame, door frame ("barn doors"), or a separate diffusion frame to transform a hard light source into a soft, flattering light. Typical applications include softening skin tones, softening hard-cast shadows, and increasing the apparent light area.

• The stronger the diffusion (Heavy Frost = powerful), the softer the light and the greater the light loss.
• The diffusion effect changes with the distance between the film and the lamp – greater distance often appears softer.
• As a heat protection measure, the usual advice for gels applies: maintain sufficient distance from the lamp and ensure ventilation, as diffusion films can deform or melt when exposed to direct heat.