For LED light bars, manufacturers express their brightness either in lumens or candlepower. For the purpose of comparing different products, you may be required to convert either of the units.
Candlepower is also referred to as candela and is used to refer to the unit used to measure photometry. Candlepower simply measures the intensity of the light from the source and does not consider the direction of light or its quality. Lumens on the other hand measure the amount of light hitting the object that is being illuminated. This makes Lumens a more complex and technical mode of measurement since it considers a human beings sensitivity to the electromagnetic emission and therefore it is can be simply considered as the amount of visible light.
Since lumens measure the amount of light in all direction while candlepower measures the light from the source in one direction, it becomes difficult to convert lumens to candlepower, however when a manufacturer rates the product in candlepower, it usually means ‘spherical candlepower’ which can be compared to a lamp rated in lumens. You simply take the lumens stated by the manufacturer and divide them by 12.57 and you will get the output in candlepower.
Of Couse Lumens and candlepower are the main features to look for when buying an LED light bar, there are several other important features you need to look at, they include;
Light bar length and shape- This is for installation purpose and affects the strength of the beam due to the number of LEDs fitted.
Beam angle- it dictates the width and depth of illumination
iii.Efficiency- This is given in lumens per watt and are a measure of the quality of the LEDs
iv.Led color temperature- this determines where the output of the lamp falls in the visible light spectrum and is measured in Kelvin temperature scale.
v.Water and power resistance- The IP (Ingress Protection) Code is the standard used by manufacturer to measure the resistance to dust and water.
vi.Electrical connectors- they should be corrosion resistance and able to perform in a wide range of temperature.
vii.Light bar operating voltage- the voltage range should cover your vehicle’s voltage