Re: Red Maglite 5D@Luminus CBM-360 4500K neutral white 5000 lumen aspheric
But CBM has lower light output as CSM in datasheet. I don't know why ...
It's not just the CSM-360 that's brighter than the CBM-360. In the Osram Ostar series, the dome-less 'LE W E3A' has an efficiency of 36 lm/W at 350 mA while the 'LE W E3B' is 50 lm/W at 350 mA (Osram pdf doc's). In JTR1962's
White LED lumen testing thread, 3rd_shift gave him a pair of P2 binned Cree XR-E's to test. The dome-less emitter only had 54.35 lumens at 350 mA, vs 70.67 lumens at 350 mA for the normal one. They weren't the same LED, so as a test it's not 100% conclusive. But considering the P2's luminosity range is 67.2 to 73.9 lumens @ 350 mA, this dome-less P2 tested as an N2 binned LED. It's reasonable to infer that dropping 3 bins in output might have something to do with the dome's absence.
As sector_cleared mentioned, it has something to do with dome reflection. I have an unconfirmed theory, and it is just a guess, the royal blue spectral peak is being reflected off the inside of the dome and causes a secondary fluorescence of the phosphor. Since this secondary fluorescence has no royal blue peak, removing the dome also causes a color shift. The dome-less emitters that are manufactured that way must have a different phosphor to appear the same color. In an actual light, the emitter having no dome is offset by the fact that being smaller or minus the dome's magnifying effect, might actually give the light a higher lux reading, dependent of course on the optics. But there is still less actual light coming out of the flashlight.
