Quote:
Originally posted by bubbletip2
So in order to single out the reflector we used the same 400w PFO Magnetic ballast and the same 400w XM 20K bulb. Here we go folks... Thanks again Justin for helping to verify the real deal between these two reflectors. 
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After looking at your numbers, that looked "interesting" to say the least, we decided to do the same test. Here are the results (with pictures). Both were done on the same 400W bulb and electronic ballast. Both reflectors were level +/- 1/16" (I'm only human). Both tests were done with the center of the bulb 20" from the testing surface (following your 21"-1" test, since we don't have the necessary water tank to do the 3" under test). The light meters are about +/- 5% accuracy depending on battery life and heat. The Lumen Bright was purchased from Custom Aquatic, the Lumenarc 3 was purchased from Lumenarc Lighting.
The most interesting note is when we did our test, the difference between 0" under and the LB and 18" out, is roughly 95% light loss (pic:LB0and18), vs. your test, which showed only a 75% light loss. The lumenarc lost 80% of it's light to this similar point, where your test showed only a 50% loss. I'm puzzled as to what could cause a discrepancy this big. Was your meter level when you took your readings?
I also included some points you may have missed, the diagonal points. To cover a 2X2 area, you need to go 18" diagonal to cover the corners. I have included 9"X9" (13" away) and 12"X12" (18" away), where the lumenarc's spread pulls away.
..... LB LA3
0" 632 380
3" 597 375
6" 501 328
9" 340 252
12" 173 175
15" 74 116
18" 33 76
9X9" 105 191
12X12" 41 107
The LA3 is 250% brighter at the 2'X2' corner.
(pic:LA12diag vs. LB9and12diag)
And here are the pictures:
