# Why do LEDs seem brighter than the same size incandescent?



## witness (May 22, 2014)

I just replaced my 60 watt living room ceiling incandescents with 60 watt equivalent Phillips LEDs. Even thought the lumen output of the LEDs is lower than the incandescents they seem brighter. Any thoughts on why?


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## ninicool (May 22, 2014)

witness said:


> I just replaced my 60 watt living room ceiling incandescents with 60 watt equivalent Phillips LEDs. Even thought the lumen output of the LEDs is lower than the incandescents they seem brighter. Any thoughts on why?


that depenps on the lumens ,incandescent light effect in 10-15LM/W,if Philips 60w led bulb have 850lumens ,in fact this bulb is more than an 60w incandescents bulb .


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## berry580 (Jun 1, 2014)

The "60 watt equivalent" led is only an approximate, probably an underestimation as they're more likely to be sued by consumer watch dogs if the led bulbs they advertise had a higher output than if it was actually lower.


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## degarb (Jun 1, 2014)

Perhaps also, warmer light may seem like less lumens than a neutral of same lumens. At least, in a low lux situation. Scotopic/photopic, blah, blah, blah. Feel free to correct me if you think I am wrong, anyone.


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## TEEJ (Jun 1, 2014)

degarb said:


> Perhaps also, warmer light may seem like less lumens than a neutral of same lumens. At least, in a low lux situation. Scotopic/photopic, blah, blah, blah. Feel free to correct me if you think I am wrong, anyone.



Short Version - MOST people find whiter light to be "Brighter".

Warmer light looks "Dimmer" in comparison.


IF the ˚k is cooler for the LED than the incan it replaced, that's typically the effect you're discussing. In museum lighting, etc, they run into that all the time.


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## steaduecf65 (Jun 7, 2014)

in fact this bulb is more than an 60w incandescents bulb .


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## hdossett (Jan 14, 2015)

Had this effect in my RV. LEDs are directional, vs omni-directional for the fluorescent tubes so the fixture didn't eat up a lot of the light. Used 70% of the lumens for the same effect. Same Kelvin.

H


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## Anders Hoveland (Feb 16, 2015)

witness said:


> Why do LEDs seem brighter than the same size incandescent?


This is not really true. Of course, LED is more _efficient _at producing light, so a 15 watt LED is going to be very much brighter than a 15 watt incandescent, but there is no clear absolute equivalence between LED light and incandescent light. LED light is much more directional, and the spectrum of wavelengths emitted is not the same either. So you take an LED that is claimed to be "equivalent" to a certain wattage, it may be "brighter" in some ways, not as bright in other situations.

Some time ago I bought a "110 Watt equivalent" LED flood bulb, but trying to use the light to illuminate a whole room, it really only seemed to put out as much light as a 70 Watt incandescent bulb. Maybe what they actually meant by "110 Watt equivalent" was that it was equivalent to a reflector/flood incandescent bulb, that also was designed for long-life (less hot filament). Marketing can be a little misleading.


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## SemiMan (Feb 16, 2015)

Directionality of the bulb could be in play, or as many have pointed out, for all the "equivalence" of lumen ratings, the blue bias that may be in LED bulbs and higher CCT can result in higher perceived brightness though Philips are often fairly warm.

However, if you have a dimmer on the circuit, the most likely reason is the dimmer, even on max setting is lowering the output of the incandescents while the LED bulbs will put out maximum power at the max setting of the dimmer, even ones designed to reduce power by 15%.

Semiman


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## FRITZHID (Feb 16, 2015)

SemiMan said:


> However, if you have a dimmer on the circuit, the most likely reason is the dimmer, even on max setting is lowering the output of the incandescents while the LED bulbs will put out maximum power at the max setting of the dimmer, even ones designed to reduce power by 15%.
> 
> Semiman



That depends on the dimmer in use. Many dimmers have a "bypass" of sorts that mechanically connects the "hot" lead past the dimming circuit which allows 100% unmodulated AC to the load.
Test with a VOM and check pre and post dimmer voltage, and drop will indicate that there is no bypass feature on said dimmer.


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## SemiMan (Feb 17, 2015)

FRITZHID said:


> That depends on the dimmer in use. Many dimmers have a "bypass" of sorts that mechanically connects the "hot" lead past the dimming circuit which allows 100% unmodulated AC to the load.
> Test with a VOM and check pre and post dimmer voltage, and drop will indicate that there is no bypass feature on said dimmer.



That would be rare with almost all modern dimmers.


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## FRITZHID (Feb 17, 2015)

Idk, I have 3 corded and 4 wall in my house and they all have this feature.


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## SemiMan (Feb 17, 2015)

Have you looked at voltage/current waveform on an oscilloscope. I would pretty much guarantee that is not the case. There are only about 3 different popular corded dimmer switches and those made in the last 5 years do not have this feature. It's a cost and failure point with no real marketable benefit as you can get to 97-98% RMS just with the potentiometer though often its less.


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