Figure 6-26. - Isofootcandle diagrams.
The isofootcandle diagrams show what the light level will be at any given point. The dimensions for the diagram are based on the mounting height (MH) of the floodlight. The aiming point (p ) is also based on the mounting height. Figure 6-27 provides a diagram for mounting heights of MH x 0.5, MH x 1, and MH x 2.
The grid pattern is also based on the mounting height. The grid line values left and right give the distance to either side of the floodlight. The values up the side show the distance in line with the aiming direction of the floodlight. The number 3, for instance, represents 3 x 40, or 120, feet from a 40-foot mounting height.
Each isofootcandle line shows where the footcandle level is the same. These lines are identified by a letter, which is used with the initial footcandle (fc) table. The footcandle values between isofootcandle lines do not change more than 2 to 1. That makes it possible to approximate the level between lines.Continue Reading