# Litetronics Compact Fluorescent-- 5K Kelvin



## pertinax (Feb 17, 2006)

Just purchased one of these (Color-Brite 50) from a local lighting supply place. No delay-- I mean NONE when you hit the switch. Beautiful colored white light, which makes the cheaper ones look sickly by comparison. About $9 each for their 20W (100W equivalent).

This 20W one is actually brighter than the usual 27W ones. 

Wow.

Only down side I can see is that I can't find an online-supplier to link to. But if you're dissatisfied with usual compact fluorescents, try one of these. 


Pertinax


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## Monolith (Feb 17, 2006)

Just one question - I have a GE 42watt that lights instantly but takes an additional 40 seconds to come up to full brightness. When you're referring to "instant on" is it full brightness instant ON?


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## pertinax (Feb 18, 2006)

Yes-- no noticable increase in brightness over the next minute.

I know the kind of behavior of which you speak-- that's what all the other ones I've seen do. Some do better than others; some outright stink.

This one's full on instantly, best as I can tell.


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## jtr1962 (Feb 18, 2006)

pertinax said:


> This 20W one is actually brighter than the usual 27W ones.


That's the difference between photopic and scotopic lumens. A higher color temperature source requires fewer photopic lumens to achieve the same apparent lighting level. Conversely, a low color temperature source may not necessarily be better even if the measured efficiency in lumens per watt is higher. A great example of this are the sodium vapor streetlights. When people first looked at the specs they actually gave more lumens with a 250 watt lamp than the old mercury vapor gave with a 400 watt lamp. However, since the color temperature was about 2000K instead of ~6000K like the old mercury lamps streets lit with sodium vapor actually appear dimmer. In fact, studies suggest that in terms of perceived lumens the sodium vapor lamps are no more efficient than a halogen incandescent. Anyway I thought you might like to know the reason why a 20 watt 5000K lamp can appear brighter than a 27 watt 2700K one despite being rated for only about 1200 lumens as opposed to 1600.



> Beautiful colored white light, which makes the cheaper ones look sickly by comparison.


Definitely. I for one really wish both the CFL manufacturers and the upcoming LED incandescent replacement manufacturers would seriously push 5000K. For too long they've gone on the assumption that people will only use the energy efficient replacements if they appear just like an incandescent. Just based on the feedback I see on this forum nothing seems further from the truth. The majority here who try 5000K or 6500K daylight seem to love it and never want to go back to the sickly yellow 2700K. Besides being easier on the eyes since your brain isn't doing any autocolorbalancing, it can also potentially save energy by providing the same perceived lighting levels with fewer lumens.


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