Grids take the form of a metal or plastic insert that you put in flash reflectors.
Various models exist for different reflector sizes. They look very much like a honeycomb, and their most important characteristic is their degree value; 30°, 20° and 12°.
The smaller the number, the narrower the beam of light is.
A grid is meant to concentrate the light and offer a more or less focused light output.
Grids are not limited to just the hair light like many tend to believe.
They can be used in a wide range of situations, such as:
It’s always a good idea to have a few grids in your bags, particularly since they don’t eat up much space.
For this comparison, I used the Reflector Grid Set 18 Complete.
I’ll show you exactly what the final result looks between the standard 18 cm 70° reflector with no grid or with either the 30°, 20°, or 12° grid.
The model was placed at 2.5 meters away from the background and the flash at 2.5 meters from her. The goal was to have a proper setup with just the standard 18 cm reflector, with the model’s shadow appearing.
Then I tried each grid to see how the lighting on the model and the background, as well as the shadow, would change.
The grids structure leads to a small loss of light. That’s why the flash power must be adjusted to match the same light meter reading for each shot.
My light meter showed a 1/2 stop difference between the bare reflector and the 30° grid, a 1/10th of a stop between the 30° and 20° grids, and a 1/3 of a stop between the 20° and 12° grids. In total, that’s about 8/10th of a stop between just the reflector and the reflector with a 12° grid.
All pictures shown in this article have only been processed in Capture One. No further retouching was applied to alter the fall-off of light.