You just watch that. . . .Beam angle

The more unscrupulous lamp manufacturers out there try a little bafflement to confuse and hide the poor performance of their product but playing with their ‘Beam angle’

Usually the light output is measured with a small hand held light meter (and a small calculation which is dependant on the ceiling height to measured surface). However it is very dependant on where the meter sits in the beam angle as to the result. (For a true measurement an ‘Integrating sphere’ is required, but with these running to £60,000+ for a 2mtr sphere not everyone can afford the outlay)

Lets say that the light meter gives us a measurement of  about 350 lumens at the centre of the beam, the further out towards the edge of the circle of light the less light you will read on the meter. If the lamp has a very small beam angle of say 15 degrees the light will be focused on a relatively small area, and be quite intense. The same lamp spreading its light over a normal 38 degree beam angle would not have the same intensity over the bigger area.

Therefore check the beam angle before you buy, anything around the 35-40 degree beam angle will be similar to your old halogen downlights, if it also gives you 400+ lumens then it might well be the lamp you are look for.

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~ by futurelamps on December 21, 2012.

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