Gaffer's Glass

Overview

The Gaffer's Glass (also known as "Gaffer Glass" or "Pan Glass") is a highly darkening viewing glass that allows lighting technicians to look directly into an illuminated light source safely and without glare. It is not classified as a fixture or lamp code, but rather as a personal assessment tool for the lighting crew – comparable to the Contrast Viewing Glass used by the camera department, but significantly darker and designed for observing the light source itself.

Through its strong filtering, the otherwise blinding source is reduced to such an extent that the brightest point of the beam – the "hotspot" – as well as the fall-off of the light cone, drop-off, and gaps become visible. The gaffer holds the glass to one eye and looks into the fixture while an assistant (e.g., the best boy or a spot operator) focuses or aims the lamp.

Construction and Variants

Several common designs exist on the market:

• Blue Ring Gaffer's Glass – the classic type, manufactured and distributed by Alan Gordon Enterprises in Hollywood, with a characteristic blue ring as its housing. It is considered the de facto standard in the US industry and comes with a housing made of 6061 aluminum with an anodized finish, a density 3.8 glass with a UV inhibitor, and an approximately 36″ lanyard for carrying.
• Filmtools ND 3.8 Gaffer's Glass – a variant with a CNC-machined housing made of 6061-T6 aluminum and a welder's glass quality density ND 3.8 glass with a UV inhibitor. It is supplied with a belt-loop pouch for attachment to a belt.

The common principle of all variants is a very high neutral density (ND) filter value (welder's glass level) in a handy housing that protects the glass from scratches and, depending on the model, can be worn around the neck on a lanyard or stored on a belt.

Use on Set

Typical applications of the Gaffer's Glass:

• Finding the Hotspot: Locating the brightest center of a fixture's beam to precisely aim it at the subject and achieve even coverage.
• Assessing the Light Cone: Visualizing beam spread, fall-off, and unlit areas.
• Checking the Filament/Bulb: Inspecting the condition of the filament or bulb.
• Locating the Sun Behind Clouds: Determining the sun's position on a cloudy day to predict shadows and matching.

As a rule of thumb, it is recommended to maintain a distance of at least approximately 3 m (around 10 ft) when looking into strong sources.

Safety Note: The Gaffer's Glass is not designed for looking directly into the uncovered sun – it is only used to locate the sun's position through clouds.