jtr1962 said:I've read that for any given intensity and color temperature a source with a higher color rendering index will appear brighter to the eye even though they measure the same on a light meter.
jtr1962 said:And to complicate things further, if two light sources have equal intensity and color rendition but different color temperatures the one with the higher color temperature will appear brighter to the eye.
winny said:Wrong.
Not true. When you push the peak beyond the 555 nm line, it appears dimmer.
I should have been clearer-up to about 6500K to 7000K higher color temperature sources of the same measured brightness appear brighter to the eye. Above about 7000K they start appearing dimmer. This was readily apparent in a local store where some daylight 6500K tubes were side-by-side with 3000K and 4100K ones. These were all T8s with around 2800 design lumens. The 4100K appeared somewhat brighter than the 3000K but the 6500K appeared way brighter than both.winny said:Not true. When you push the peak beyond the 555 nm line, it appears dimmer. (Well, it would depend on what your spectrum look like, but to sum up, it's highly likely that the turnover will come close to 555 nm.)
winny said:timcodes,
Well, it depends on what you mean by blueish white. Aften extensive LED usage, peoples references normally shift.
I don't have the exact figure, but I will try to look it up what the most efficient CCT is, but I expect it to be somewhere between 4000 K and 5000 K (which is bluish white in my eyes), depending on what your spectrum look like. For Philips 35W HE florescent tubes, it looks like this:
CCT [K] flux [lumen]
2700 3300
3000 3300
3500 3300
4000 3300
6500 3100
so you can't really tell. I'll try to do some research what peaks for blackbody radiators.
winny said:Wiz,
The question was not if you illuminated anything.
Wiz said:What is the point of a flashlight if you are not illuminating anything? Surely that is the only relevant aspect of whether or not a flashlight is brighter.
billhess said:I think the point is if you are going to use illumination as the point of reference you would have to be specific as to what you are illuminating, as everything would reflect differently. So it would tend to be more standard and easier to not have another variable in the equation. so generally we would speak of just the light emitted not the light reflected off of something.
Wiz said:But the question was which is the brightest tint, not which tint makes a light meter register the highest with the same amount of power consumption etc.
In that case surely a real world test (i.e. trying to identical lights models with different tints side by side in normal use) is as good a test as any to answer the question. After all, the tint that illuminates objects the best and reveals the most detail, is surely the best, regardless of what a meter reads.
timcodes said:Alright, what if we break it down to 3 question then?
1. Which appears to be brightest to our eyes?
2. Which is the brightest according to light meter?
3. Which is the most efficient color?
Thanks!
Wiz said:But the question was which is the brightest tint, not which tint makes a light meter register the highest with the same amount of power consumption etc.
In that case surely a real world test (i.e. trying to identical lights models with different tints side by side in normal use) is as good a test as any to answer the question. After all, the tint that illuminates objects the best and reveals the most detail, is surely the best, regardless of what a meter reads.
billhess said:Are you kidding. Which is the brightest tint is asking which one puts out the most light(a light meter) not which one reflects the most. What a joke stop trying to play with words to be right. A light meter is a real world test. To say a question like this was meant to really ask which tint would reflect the most in every different kind of surface on the earth is ridiculous.
billhess said:so the answer to your question would list 100's of surfaces and how each reflects different color's of light?