LED v/s Halogen
I promised that I would come back to the question of LED (light emitting diodes) lamps, and that I would test a 5watt MR16 type LED against halogen MR16. This post represents my initial findings.
I bought a 5 watt led on EBay from a dealer called LinLin House Taiwan. The EBay page and transaction history are here:
The advert claims that to offer a uniquely bright LED with a Cree element. The advert would appear to say that this 5 watt LED is as bright as a 50 watt halogen lamp. However, if you read the advert more carefully, with the eye of a lawyer, you will find that it is cunningly worded to avoid using any direct and clear description of the light output.
The wording of the above advert on EBay says:
In the piece near the photo:
"The brightness of our LED MR16 is double of other providers, and one 4.2 watt LED MR16 is able to replace one 50 watt halogen lamp - with similar light-out brightness as the above photo."
(Oh yes! indeed it can replace a 50 watt halogen - but it can only give just one quarter of the light.)
Further down it repeats the following:
"Many people are asking if the LED lights are bright enough to replace the traditional lights, especially for the 4.2W LED MR-16 whose power consumption is only 1/12 of traditional 50W halogen lamp. As soon as our 4.2W/2800K MR-16, which is dazzlingless design, were installed for the office lighting (as following photo) in Taipei, it is proved that our new 4.2W MR-16 is not only 2 times brighter that other LED MR-16 providers but also able to replace the traditional 50W halogen lamp to save 12 times energy."
If the advertising authorities in the EU were to legislate on the above advert, I have no doubt whatsoever that the verdict would be that it be withdrawn.
Bottom line is that the advert is totally misleading, because the LED lamp in question is no-where remotely close to the light output of a 50 watt halogen. In fact, it doesn't even fully match the output of a 20 watt halogen lamp.
The photo below was taken by placing a white photo-mounting board about two feet from the lamps, and the shot taken from a distance of 5 feet from the board.
On the left is the 5 watt LED on the right a 20 Watt Halogen
Which do you think has a brighter output?
Above is a photograph of the pools of light from the 5 watt LED on the left and a 20 watt halogen bulb on the right. You would not need to be a rocket scientist to figure that the 20 watt halogen is giving more light. The 5 watt LED comes close to the light output of a 20 watt halogen but certainly does not exceed it.
5 Watt LED does not match a 20 watt halogen.
The LED on the left above is claimed in the advertising to MATCH the light of a 50 watt halogen bulb. I say that it cannot match the light of even a 20 watt bulb. Unless I happen to have been sold a faulty LED, the advertising is totally misleading. I am contacting EBay and making a complaint on the basis of misleading advertising, and I am asking that the description is fully corrected or the seller removed.
The above photo is taken looking directly into the light of two LED MR16 type lamps, and two 20 watt halogen lamps. Not the way to tell the comparative brightness, but it gives an idea of the colour and light scatter. From the left it reads:
5 watt LED
20 watt Halogen
20 watt Halogen
3 watt LED
LEDs still have a way to go
LED lamps still have a way to go yet. A 5 watt LED can reasonably replace a 20 watt halogen bulb for light output. The colour is fairly good and the light output is maybe 10% less than the halogen. But with the cost of the LED you might think twice about the value.