I think the camera cause the LEDs to look better then the HPS, as LEDs still far less efficient then HPS lamps.
The Philips Cosmowhite CPO-TW are more efficient then induction fluorescent and most CMH and regular HPS lamps (Max 118 lm/w for the 140W) because of the use of low pressure xenon instead of argon, and the use of cerium and sodium iodides and a new base (PGZ12).
Dor, there's no xenon in the CosmoWhite lamps, only argon - and this month Philips released the second generation CPO lamps which now feature 126 lm/W for the 140W model, whith a CRI at 70 now.
As for the LED streetlight shown here, I am not very impressed as there is absolutely not light control; it only gives a pool of light beneath the luminaire and nothing between the poles ... that would be a "no go" if it was me ...
Max, James said me that the CosmoWhite lamps uses xenon as a buffer gas.
The chemistry of cerium and sodium together with a xenon filled arctube of special dimensions to minimise thermal losses is what results in the remarkably high luminous efficacy, he said.
See my post in LG site about the CosmoWhite CPO-TW.
Dor, I can certify you that CosmoWhite lamps are filled with argon, not xenon - however, he is correct that the cerium-based chemistry and the long an thin burner are essential to the high efficacy of the lamp. the reason for that are that cerium is a very efficient green emitter, and the use of a long electrode distance enables lower mercury pressures to be used, which critically reduces the amount of radiated infrared and avoids the broadening of the red-wing sodium emission into the IR domain.
Form109 >> Yep, that's pretty much the highest efficacy one can get with a decent white light HID lamp! In fact, what makes MH so interesting is not only this kind of efficacy, but also the fact that they are reasonably priced (i.e. to be compared with LEDs...) and they have very high lumen packages in very small volumes which enables the design of compact and stylish luminaires. Did I also mention that you could even dim these Cosmos to 50%?
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The Philips Cosmowhite CPO-TW are more efficient then induction fluorescent and most CMH and regular HPS lamps (Max 118 lm/w for the 140W) because of the use of low pressure xenon instead of argon, and the use of cerium and sodium iodides and a new base (PGZ12).
As for the LED streetlight shown here, I am not very impressed as there is absolutely not light control; it only gives a pool of light beneath the luminaire and nothing between the poles ... that would be a "no go" if it was me ...
The chemistry of cerium and sodium together with a xenon filled arctube of special dimensions to minimise thermal losses is what results in the remarkably high luminous efficacy, he said.
See my post in LG site about the CosmoWhite CPO-TW.