One of the tests I ran on all the flashlights included measuring the LED brightness and light duration. I didn't have a lab full of sophisticated equipment but I wasn't going to rely on the old "calibrated eyeball" method either. My best method I could come up with for performing a brightness comparison resulted in my acquiring a Gossen photography light meter from a friend and using it to measure the output of the various flashlights. I was not trying to determine the actual candle power output of the flashlight but merely wanted to be able to compare relative brightness using a consistent measuring method.
The brightness and duration test was performed in the following manner. Two identical height benches were positioned 6 feet from each other. On one bench, the Gossen light meter was positioned so that it would be directly illuminated by the flashlight under test. On the other bench, markings were placed on the bench surface to ensure accurate placement/alignment of the flashlight towards the light meter. The placement of the light meter was on or about the center of the light beam. A stop watch was used to time the duration of the illumination period. The test was conducted in an interior room with ambient light supplied by overhead fluorescent light fixtures.
All flashlights had seen prior use (charging and discharging) within the 24 hours preceding the brightness test. As such, none were completely discharged (this was verified prior to the start of the brightness test). Since all of the directions provided with the flashlights state the times required to recharge the flashlights, two charge times were selected and used on each flashlight during the test. The first charge cycle consisted of 2 minutes of "shaking" at the suggested 2-3 shakes per second. The second charge cycle, which immediately followed the first run of each flashlight, was limited to 1 minute of "shaking", again using the suggested 2-3 shakes per second method.
It was also my intent, during this test, to try to discount any influence in LED brightness that may be a direct result of the storage capacitor's long term storage "quality". A higher quality electrolytic capacitor has less leakage than a lesser quality unit. If you were to fully charge a low quality capacitor and let it set for a period of time, you would find that the capacitor had self discharged to some level. To reduce that affect on this test, the flashlight to be tested was first charged and then immediately placed onto the test bench where the brightness and duration test was conducted. Once that phase of the test was completed, the same flashlight was recharged using the criteria for the second charging cycle. Again, it was immediately placed onto the test bench where the brightness and duration test was conducted. This testing process was applied to each flashlight.
I did not use a standard set of times while monitoring the duration of the light (ie. 1 min., 2 mins., 5 mins., 10 mins., etc.). Some of the actual times were fairly short while others were significantly longer. I believe the times noted will provide you with a good indication of the flashlight's initial brightness (start of test) and the point where meter detectable light output ceased.
The units of measure for the light intensity values recorded in the tables below equate to absolutely nothing. There is no direct correlation between the numbers recorded and foot candles of light. It provides a means by which the light intensity of all flashlights, tested in the above manner, can be compared to each other.
Here are the results as I recorded them:
|Nightstar||1||0||3+ (off scale)||2||0||3|
The Nightstar was, without a doubt, the brightest and longest lasting model tested. The numbers proved it. Although the smaller size of the Nightstar RS may give you the initial impression that it is a lightweight contender, its number made a good showing which put it in 2nd place. Yes, the Hummer was initially a bit brighter than the RS, but its output faded to zero while the Nightstar RS continued for two more minutes.
As for the Everlast and Forever flashlights, the Everlast was a bit brighter
initially compared to the Forever. They both turned in poor durations of
just 4 minutes. Given that both were initially charged for two minutes but
yet provided only four minutes of light, the owners of these two lights will
certainly develop good arm muscles.....charging those lights is pretty good
exercise. One other comment in regards to the Everlast, the switch was
just plain stupid to mess with. Find a roll of tape, locate a nut in the
garage of the appropriate size, charge the light, press the nut onto the switch
and wrap tape around the flashlight, click on the stop watch, etc.
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