- Joined
- December 28, 2010
- Messages
- 37,580
- Reaction score
- 3,995
- City, State
- Russell, Ontario (Ottawa area)
- Year, Model & Trim Level
- 2023 Aviator Reserve 201A
- Callsign
- VE3
Check the chart in post 21. As the 'K' number goes up, the lumens output goes down. It is that way on every site I have looked at.Peter this is quite untrue.
Color temperature and light output in lumens are essentially unrelated in an abstract sense.
e.g. If I buy an 8000K and a 6000K bulb I won't know which is brightest in lumens - it could be either one.
Similarly I can buy an old style high power floodlamp of several thousdand watts @ approx 3500K and it will be very very very bright (in lumens)...
If I have a single incandescent lamp its brightest point (in lumens) before it finally burns out (as I increase the supply voltage) will be its highest color temperature. It will likely be the apparently brightest point too.
Now above a certain point (~7000K) "useful" (to humans) apparent light intensity does diminish as color temperature goes up - personally I find Purple light to be highly objectionable - and I would expect rather useless for driving. Besides for me at least, accurate color rendering is highly beneficial to recognition at night (so I don't like sodium street lights either).
At lower color temperatures (say 3000K-6500K) the apparent brightness to humans actually increases with increasing color temperatures.
Think of it like this - as humans we are optically attuned (and optimized) to the natural daylight we have all day long (~6500K) - makes sense that we perceive less brightness as we diverge - either way - from that color temp.
Alan
6000k = approx. 2900lm, 8000k = approx. 2500lm output while 4300k = apprx. 3100lm.
Peter