Lighting
Gobo
Definition
A gobo is a thin metal or glass disc placed in the gate of a profile (ellipsoidal) spotlight to project a pattern. Metal gobos carry cut-out patterns such as breakups, foliage or windows; glass gobos can reproduce detailed images, including full-colour photographs. Common standard sizes include A (100 mm), B (86 mm) and M (66 mm), given as outside diameters. Each fixture accepts a given size, so gobos are not interchangeable between fixture types.
In the field
A common error is to arrive with A-size gobos for a fixture that takes M-size. The size a fixture accepts is therefore checked in its documentation before show day.
Sources
- Rosco, Standard Gobo Sizes : diamètres extérieurs A 100 mm, B 86 mm, M 66 mm et diamètres d'image · us.rosco.com
- Wikipédia (pointeur secondaire), Gobo (lighting) : gobos métal et verre, placement au foyer · en.wikipedia.org
- Shelley, A Practical Guide to Stage Lighting, 2e éd., Focal Press, 2009 : découpes et gobos