On Thu, 26 Nov 2009 14:58:02 +0000, John wrote:

It is a pity we are 'stuck' with relating brightness to wattage. If we used
a proper definitive measure of brightness then manufacturers would have to
be more honest.

Stick 1000 people in a room and get them all to rate the brightness of a
particular bulb on a scale of 1-10? :-)

Problem I have is that brightness is only part of what makes a light
'good' for a particular application, so just saying that one bulb gives
off as much light as another isn't necessarily good enough.