
www.FraenOMG.com 4/8 F360L-3C-S for Rebel/Rebel ES, Rev 02
Illumination Calculations
To calculate the intensity (candela) at a specific angle, read the candela/lumen value from the graph in
Figure 1, and multiply this value by the total flux of the Luxeon Rebel LED used. Refer to the Luxeon
Rebel LED datasheet for nominal lumens values. For a more accurate calculation, refer to the intensity
“ranking” (binning) tables on the datasheet for the specific LED.
Example calculations:
If the Fraen F360L-3C-S is used on a cool neutral white Luxeon Rebel ES LED at 350 mA, a typical
luminous flux of the LED is 80 lumens.
The calculation is: (0.22 candela/lumen) x (80 lumens) = 17.6 candela, at ±69º off-axis.
At ±45º and ±85°off-axis, the intensity is ½ of the peak. This means at ±45º and ±85° off-axis, the
intensity should be 1/2 of 17.6 candela, or 8.8 candela.
One candela at 1-meter distance produces 1 Lux. The peak intensity at 1 meter will be 17.6 lux. The
intensity decreases as a function of the distance squared. At 2 meters the peak intensity will be 17.6 /
(22) = 4.4 lux. At 3 meters distance, the peak intensity will be 17.6 / (32) = 2.0 lux.
Mechanical Characteristics
TOLERANCES: +/-0.2 mm
Figure 2. Dimensions of the F360L-3C-S lens