Originally posted by: Apex
Originally posted by: JulesMaximus
Originally posted by: Apex
Yeah, not only is it all over Google, but it's even easier to see with HT applications, since many more people use light meters to measure output. There's quite a bit of loss, regardless of whether we're talking about filament based light sources, or arc type.
Read my reply above.
Hmm, how much depends on the type of bulb. Halogen's drop off tends not to be quite as steep as some competing technologies, probably not more than 30% for a well designed bulb. Xenon arc can lose almost 50% over its lifetime. NSH loses probably 30-40% as well, depending on the design. P-VIP, SHP, and UHP tend to lose a bit less.
We have to remember though, our eyes do not perceive light in a linear fashion. We see light on more of a logarithmic scale. Thus, a doubling of output is perceived as only a small bump in light.