Grids (light modifiers)
The aim of a grid is to create a more directed light. Very often studio lights come with a grid as an accessory. Often fitted to softboxes the grid prevents the soft light created by the soft box from illuminating the surrounding area. It channels the light at the subject without creating a soft light influence on the surrounding parts of the scene. It preserves the character of the light whilst preventing it becoming a hard light.
A grid is similar to a Honeycomb grid but is much more open. The size of each grid cell can vary. Although they are consistent across any particular grid, different grids vary in their grid size. Smaller grids may have each cell as small as say, 20mm. While larger grids could have grid cells as much as 100mm or even 200mm.
Grids in general act to prevent light spreading out sideways, or diffusing, from the source. This acts to direct the light so it is able to be more controlled. It affects the subject it is pointed at and does not illuminate the surroundings. A tighter grid will direct the light more effectively. A more open grid will allow light to spread out more. The tighter grids exhibit a tendency to harden the light. An open grid will tend to be softer. The nature of the grid therefore affects the light in different ways. Studios will tend to have a range of grids available so as to be able provide the type of light required for the wide range of different studio circumstances.