The power of a lamp is in lumens. It is actually measuring the luminous flux.
This measurement is made by means of an integrating sphere (or sphere). Unfortunately, this equipment is very expensive and cumbersome, to the point that practically nobody has it. Moreover, it is always more commercially advantageous to announce fanciful figures, which are very exaggerated in relation to reality, and we must admit that most manufacturers and distributors do not deprive themselves of it. Some are satisfied with very optimistic theoretical estimates, but others have no qualms about announcing figures without any technical basis. Some make the effort to specify that the power announced corresponds to that at the level of the led and not that at the output of the lamp, but even in this case, the announced figure is generally exaggerated.
Some are satisfied with very optimistic theoretical estimates, but others have no qualms about announcing figures without any technical basis. Some make the effort to specify that the power announced corresponds to that at the level of the led and not that at the output of the lamp, but even in this case, the announced figure is generally exaggerated.
Indeed, many things affect the amount of light actually emitted by a led, and most of them are too often ignored when commercial interests are at stake: The bin of the LED that determines its output, ie the amount of light emitted at equal power (electrical) power.
Uses of high power LEDs
High powered LEDs are commonly used in flashlights. View some of the best tactical flashlights to see some examples of these type of lights. These lights are commonly used outdoors and by security/military personnel.
Hue: As a general rule, at equal power consumption, the amount of light emitted is all the more important as the hue is cold.
The temperature of the LED, which heats enormously in gold operation, the efficiency of an LED is all the worse as the temperature is high. Theoretical figures are generally based on ambient temperature, which is totally unrealistic in normal use (as opposed to a laboratory test with a specific cooling system).
To all this are added the losses generated by the reflector and the lens, of the order of 15%, and the current actually discharged by the regulation circuit, sometimes well below the announced current.
The lumen figures should therefore not be taken into account but should be subject to the greatest distrust because they often reflect a desire to deceive potential customers about the real power of a lamp.
The only way to objectively estimate the power of a lamp is to compare it to that of another lamp, either directly or through beam shots, provided of course that these pictures have been made in accordance with the rules of the art, under identical conditions and settings.