Originally Posted by
Looigi
Watt rating is one of the least useful as it's the power input to a light, not the light output. For example, a 1W incandescent bulb would be useless as a bike light whereas a 1W LED could provide a useful, albeit rather low, amount of light because LEDs are much more efficient than incandescent lamps.
Lumens is a measure of total visible light output. Accuracy and truthfulness of measurements vary. How that light is distributed is also important. Lux is a measure of the maximum brightness in a beam (Lumens per square meter). For a given Lumen output, a more tightly focused beam provides higher Lux. Taken together, Lux and Lumens give a descent idea of how a light might perform, but they still only convey the total light output and the brightness at the center of the spot, not how the light is distributed around the center of the beam.
The one thing I would add is that for a lux measurement to be meaningful, you have to have the distance from the light to the target.
Originally Posted by
rekmeyata
But again not all light manufactures rate their lumens honestly. The only way you can determine a light's effectiveness is to look at the comparisons sites I mentioned in my first post, unfortunately not all the lights on the market are shown, but at least most of the major brands and a couple of generic Chinese brands are.
I would say that most light output claims are inflated. However, since they all inflate them about the same, comparisons can still be made. Although you linked to MTBR's light shootout, pictures of beam shots can be misleading by themselves. MTBR does a good job of using the same camera settings for all of their light pictures but their exposure times are too long. To their credit, MTBR does use an integrating sphere to measure the true lumen output which can be found
here. Based on my experience with the Magic Shine and generic Chinese Crees, I would put their output at about the same level...i.e. around 700 lumens. Which is about what you can get out of a overvolted MR11 halogen or their output is about the same as you could get 15 to 20 years ago.
Originally Posted by
rekmeyata
I do believe the wave of the future, started by Phillips, will indeed be aimed optics, so instead of a round flashlight beam requiring 3 to 4 times the power they will be more like motorcycle and car headlights where the beam is aimed flat, after all no one cares about seeing the tops of trees! And as a bonus as the light output drops but illumination increases your battery can be smaller and could last longer depending on how small the battery gets of course. This inaccurate reporting of lumens by manufactures is very much akin to the highly inaccurate wattages reported by consumer home electronics, a $350 Sony surround sound receiver in no way puts out 1200 watts of sound while only consuming 45 watts.
I don't see aimed optics having much future at all. The wave of the future is the $20 Cree. I would say that "requiring 3 to 4 times the power" is overstating the difference. The MTBR beam shots certainly don't show that kind of difference. Even if the Phillips had "3 to 4 times the power", a $20 price tag on the Crees means you can purchase multiples and get to that level of power. The $200 price of the Phillips makes having more than one prohibitive.
Originally Posted by
rekmeyata
An even better example of the wave of the future. These lights are incredibly small. Small enough that you could mount two on the bars and one on the helmet and approach Battle of Britain seachlight status. And, at $30 per unit, you'll have plenty of money left over for other stuff. Phillips and other more expensive lights just can't compete.
If only they didn't look like 1950 ladies' glasses.