Luminous Flux

							Luminous Flux
Luminous flux is the quantity of light energy per
unit time arriving, leaving, or going through a
surface. Unit of luminous flux is lumen(lm)
Luminous Intensity
Luminous intensity is the light energy per unit
time emitted by a point source in a particular
direction. It is measured in candela(cd)
Illuminance
It measures how much energy has fallen on a
surface. The lux (lx) is the International System
(SI) unit of illuminance.




    lm (lumen)—Measures the overall output
     power of the light (luminous flux). A 100-
     watt general purpose light bulb has a
     luminous flux of about 1750 lm.
      cd (candela)—Measures the maximum
       luminous intensity of the light, usually along
       the direction of aim. a 100-watt general
       purpose light bulb has a luminous intensity of
       about 139 cd.
      lx at (lux)—Measures illuminance caused by
       the light shining on a surface at a certain
       distance and facing in the direction of the
       source. The lux is the International Scene
       unit,




Common Lamp Values for Photometric
Lights
The following table lists some commonly used lamps values that you can use as a guide
for defining photometric lights. The information in the table is approximate; however,
you can refer to manufacturer’s documentation for more precise photometric data for
these lamps.

General Purpose Lamps
Note: In the tables below, “Class.” stands for “Classification”; the values under
“Intensity” are expressed in candelas.



  Class.    Watts Type Intensity Beam Field
 Class.     Watts Type Intensity Beam Field
A-19/ Med 60         Point 70
A-19/ Med 75         Point 95
A-19/ Med 100        Point 139


M16 Low Voltage Lamps


   Class.       Watts Type Intensity Beam Field
Narrow Beam 20          Spot 3300    6    12
Narrow Beam 50          Spot 9150    12   25
Medium Beam 50          Spot 3000    25   50
Wide Beam       20      Spot 460     38   75
Wide Beam       50      Spot 1500    38   75


Par36 Low Voltage Lamps


   Class.       Watts Type Intensity Beam Field
Narrow Beam 25          Spot 4200    9    15
Narrow Beam 50          Spot 8900    10   15
Medium Beam 50          Spot 1300    30   60
Wide Beam       25      Spot 250     36   75
Wide Beam       50      Spot 600     39   75


Par56 Line Voltage Lamps


    Class.  Watts Type Intensity Beam Field
Narrow Beam 300 Spot 68000       9    15
Narrow Beam 500         Spot 95000   9    15
Medium Beam 300         Spot 24000   18   36
Medium Beam 500         Spot 47500   18   36
Wide Beam       300     Spot 10000   30   60
   Class.    Watts Type Intensity Beam Field
Wide Beam    500   Spot 18000    30    60


Par38 Line Voltage Lamps


    Class.  Watts Type Intensity Beam Field
Narrow Beam 45    Spot 4700      14   28
Narrow Beam 75     Spot 5200     12    25
Narrow Beam 150    Spot 10500    14    28
Medium Beam 45     Spot 1700     28    60
Medium Beam 75     Spot 1860     30    60
Medium Beam 150    Spot 4000     30    60


R40 Line Voltage Lamps


   Class.   Watts Type Intensity Beam Field
Narrow Beam 150    Spot 5400    22    50
Wide Beam   150    Spot 1040    76    130
Wide Beam   300    Spot 1950    76    130