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Comment by justin66 | Hacker News Reader

Is that really the typical CFL number? I ask because I've got one of the new Cree bulbs and I find the quality of light really a lot better than that of the (admittedly cheap) CFLs I've bought at Costco.

So I guess I'm struggling with the significance of CRI.

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It depends on which CFL you buy of course. But 90 CRI CFLs are easy to find.

In general "warmer" CFLs have a better CRI.

You can trade off energy efficiency for CRI. This is true for LEDs as well. So if you don't need great color then go for a lower CRI since you'll save energy on the light output.

But because of that, when comparing energy efficiency of LEDs vs CFLs you MUST use a comparable CRI, otherwise it's not a fair comparison.

But I'll save you time: There are no commercially available LEDs that beat CFLs in energy efficiency for the equivalent CRI.

I've found the exact opposite. I've found that there are many more "cooler" (~5600K color) CFLs with a high CRI than warmer (~2700K color) CFLs with a high CRI. The cooler 5600K lights are daylight balanced and used a lot with digital filmmaking and as indoor grow lights, whereas the warmer lights are used in home light fixtures to approximate the color temps of incandescents.

Thanks. That's a good way to sum things up.

As someone who is enthusiastic about LEDs from a distance (I'm not about to run out and replace all my lights at once) I'm comfortable with the idea that LEDs are still a couple of generations away from replacing existing technology in a satisfactory way. But damn, those generations sure are happening fast.

I became aware of Cree because of flashlight LEDs and what they accomplished in that space over the course of a year or so was pretty amazing. At present I can still take out my little AAA light with the newest Cree LED and say "check this out" and surprise people with its brightness. The early LED flashlights were largely junk, but in contrast, this is a great use of the technology.

Even the top-of-the-line CREE bulbs are only suitable for people who are color blind or habitually not paying attention. I once did an ill-considered change from halogen to LED bulbs in my kitchen, and having done so could no longer see the colors on my dishware. That was ridiculous. I went back to the halogens. My house is in a year-round heating climate anyway so I don't really worry about the waste heat from them.

I wonder if you've actually used one of the newest Cree bulbs? I'm not color blind and I found the color of one of their 2700k bulbs to be better than the CFLs I use in a few places. Come to think of it, they're a fair bit better than the g7power LEDs as well.

This is why I'm wondering if the CRI is really a magical "light goodness" benchmark number or what. Some people certainly seem to be treating it that way.

They were the best ones I could get my hands on. I believe their advertised CRI is 90. If you look at the spectrum though, they are still quite peaky/notchy. Halogens are very close to sunlight. Halogens with clear bulbs have CRI 100 by definition.

Yes, the latest LEDs are far superior to CFL. And oatmeal tastes better than dog shit.

Another thing to consider is that radiation outside of the visible light spectrum may have positive effects. For instance, halogens radiate a lot of infrared radiation, which is used in various therapies and is a big part of why being out in the sun feels so good.

cri doesnt mean too much absolutely, but it's the metric the standards associations chose to compare lights. after working with medical lighting for a while I've found myself paying more attention to the combination of cri and cct and/or cri and luminous flux. what people need to realize is that lots of other factors come into play such as ambient color mismatch and bleeding of adjacent colors. in some conditions even high cri lights don't appear to show color very well.

Chandeliers with prismatic glass are another problem area for LED lighting. My home has two such fixtures, previously populated with nine 40-Watt incandescent lamps each.

That's a lot of power dissipation (360 Watts), particularly since one of the fixtures was on up to 12 hours per day (4KW-h almost daily for that).

So I replaced all nine bulbs with TCP LDCT3WH30KCC 3-Watt (15 W incandescent luminance equivalent) 3000-K 80-CRI bulbs. 27 Watts, down from 360.

Excellent energy savings, excellent dimmability (better than the incandescents), but all those beautiful violet, green, blue, gold and other various facets of color from the prismatic glass were just gone -- collapsed down to a cold white; as if the glass weren't prismatic anymore.

I do not understand why I don't see at least some narrow-band stripes of some few individual colors.

So I put back just two 40-watt incandescent bulbs. That was enough to bring back a nice refractive color spread from the prismatic glass. The dissipation is up to 91 Watts from 27 Watts, but it's beautiful again.

Energy problem resolved satisfaction (75% reduction), while keeping the aesthetics alive too.

That's pretty interesting. I bet it has something to do with the polarization of light. If so a bulb like the Cree (with its glass casing) might help, although it might look goofy in that particular fixture.

I doubt it's the polarization. More likely it's that the incandescents are point, or line sources (non-frosted bulbs), but the LED's are much wider - so you are still getting colors, but since you have multiple color in multiple spots they overlap, mix, and are back to being white again.

Try to get LEDs that have no diffuser lens in front, since the LED itself is a point source.

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