harrad

Born420,
There is a significant difference between the initial and mean lumen ratings.

Mean Lumens: The average light output of a lamp over its rated life. For flourescent and metal halide lamps, mean lumen ratings are measured 40% of rated lamp life. For HPS lamps, mean lumen ratings are at 50% of rated life.

Initial Lumens: The light output of a lamp taken after the lamp operation has stabilized. Typically this measurement is taken at 100 hours of use.

Those that sell lamps prefer to use the initial lumen ratings which are the most flattering for there purposes. Those who design lighting systems use the mean lumen ratings for calculating overall, long term results. Mean lumen figures are not very relavent to growers since most replace their lamps before the 50% mark. Rest assured, what you see printed on the box is initial (new) lumens.First lets dispell the myth that Standard HPS lamps suffer from a sharp drop in output with age. Following is the breakdown on lumen depreciation for various types of lamps, this is the point at which the Mean lumen rating is taken:

All standard HPS lamps (Except the 35W) down 10% @ 12,000 hours.
Son/Agro and other HPS agro lamps, down 18% at 6,400 hours.
Standard 400W Metal Halide lamps, down 33% at 6,000 hours.
Standard flourescent lamps are typically down 10% @ 8,000 hours.

As you can see, lumen depreciation is LOWEST for standard HPS lamps.

Another warning flag is LOA's claim that the Fluorex outputs up to 500W of light. A 500W Quartz Halogen outputs about 10,500 lumens so what are they comparing to? Less efficient 100W lightbulbs? Ladies and gentlemen, Welcome to marketing 101. In marketing 201 we will cover "how to spell check your boxes before printing" I wouldn't know what to do with a long life "Blub" if one bit me on the a**.
Standard H4 headlight lamp, aproximately 1600 lumens.
New HID headlamps, aproximately 2400 Lumens new, 1700 lumens mean.

Peace & Good Growing, Harrad.