A lumen is a measure of how much total light a bulb produces. Incandescent (1156) bulbs spray their light through almost 360 degrees and lamp housings designed for them rely on that. Most LED lamps put all their light out in a narrow cone and work poorly with standard 1156 housings. However, there are LED assemblies that have their light-producing chips arranged around a sphere and they work well in standard housings.
The LEDs you see on commercial vehicles are mounted in housings designed for their narrow cone output, that's why they look bright.
A standard 1156 bulb puts out about 400 lumens when new. As of January 2010, I haven't found an LED replacement that puts out any more, and most are only 50 lumens or so, not enough for a standard 1156 housing.
To confirm the above: From Bosch Automotive Handbook7th ed. a 1156 (BA15S) Stop/Turn 21W bulb puts out 460 lumens. For a 5W Side marker / Tail BA15S it is 50 lumens (strangely low, I know) and 10W Tail light 125 lumens.
If replacing with a warm white LED, then that is how many lumens you need to match the brightness (as well as light direction being good). BUT, if using a Red LED for a brake light or an Amber LED for Turn signals, then less lumens are needed. This is because the Red lens of a brake light filters out all the blue, yellow, green, etc out of white light, but filters nothing from a Red LED. The question now is: What is the percentage of "Red" in the light output of a "White" incandescent bulb?
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An 1141 bulb consumes 18.4 watts.
A 1,000 watt is 15,000 lumens. A 100 watt bulb is 1,500 lumens.
Brightness is measured in lumens so the bulb has a brightness of 100 lumens. The electrical power the bulb uses is measured in watts. The efficiency of a bulb is expressed in the number of lumens produced per watt of electric power.
Lumens measures how bright it is, watts measures how much electric power it uses up. An old-type incandescent bulb produces about 10 lumens per watt. A halogen produce about 13 lumens per watt. A fluorescent (energy saving) bulb produces about 50 lumens per watt. LEDs produce somewhere around the same as a fluorescent.
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An 1141 bulb consumes 18.4 watts.
A 150 lumen red LED will be as bright if the tail light lens is red. A 220 red led will be brighter than a regular 1157. The colored lens will make a white led bulb not as brighter due the filtering affect it has on the light wave lengths. A white LED replacement would have to be 400 lumens to equal the 1157's brightness.
A 1,000 watt is 15,000 lumens. A 100 watt bulb is 1,500 lumens.
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Brightness is measured in lumens so the bulb has a brightness of 100 lumens. The electrical power the bulb uses is measured in watts. The efficiency of a bulb is expressed in the number of lumens produced per watt of electric power.
Lumens measures how bright it is, watts measures how much electric power it uses up. An old-type incandescent bulb produces about 10 lumens per watt. A halogen produce about 13 lumens per watt. A fluorescent (energy saving) bulb produces about 50 lumens per watt. LEDs produce somewhere around the same as a fluorescent.
Approximately 15 lumens per watt for halogen, so 300 lumens.
A 150 watt halogen bulb will give off somewhere around 2000 lumens. These lights may give off up to about 2400 lumens.
The number of lumens produced by a 34 watt bulb depends on the type of bulb. As a general estimation, a standard incandescent bulb produces around 400-500 lumens per 40 watts, so a 34 watt bulb would likely produce slightly fewer lumens, around 350-450 lumens. However, different bulb technologies such as LED or CFL can produce a higher number of lumens with lower wattage.
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460 lumens for a standard automotive, not uprated.