LED, CFL and Incandescent bulbs side by side | Hacker News Reader

LED, CFL and Incandescent bulbs side by side

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38 pointsAndrewDucker39 comments

Isn't the issue really more about the quality of the light, which can't be captured in photos? CFLs give me headaches after a while, just like big florescent office-style lights.

In my personal experience, the difference between a crappy CFL and a good CFL is huge. Low-end CFLs are dim, flickery, have a large warm-up period and often worse color. High-end CFLs, on the other hand, can have really nice quality light, good color balance (though I used whiter "full-spectrum" incandescent bulbs, so YMMV), and very little in the way of noticeable warm-up time.

You may still dislike CFLs and that's fine, but you may also have just been exposed to crappy ones.

And it's important to mention that "high end" CFLs now cost about $1 each. You can get bulbs at Home Depot for $4 for a pack of four that turn on immediately, don't flicker, and are available in three color profiles including a warm one that looks very much like an incandescent.

Also important to mention that it is non-trivial to tell the difference between a good, bad or indifferent CFL. Frankly, I'm not interested in doing a product comparison or multiple return trips on a lightbulb.

Where LED is valuable for me is in the dimmable category. I have "dimmable" CFLs and they are terrible, they barely dim and if you lower the dimmer too far they either blink or go off entirely. CFLs are just not dimmable.

Where LED is valuable for me is the absence of mercury. I break an incandescent bulb in my home at least twice a year.

The receptors that cause light to be painful are sensitive to the blue part of the spectrum. Fluorescent tubes tend to load up on that part of the spectrum because it is cheap to do so and high color temperature used to be a luxury feature, not because there is any technical reason to.

Yellow "bug light" CFLs do not cause headaches for me, and are easy to read by. Unfortunately the color rendition is ... poor. It seems that there is no middle ground with CFL engineers.

I could be wrong about this, but isn't it pointless to do side-by-side comparisons using a device that requires specific white balancing. A camera is not going to capture the same result your eyes will.

You can capture the relative difference and if you keep the same white balance setting (or, more likely, apply the same setting to the raw photograph in post) it’s even possible to compare different photos.

What those photos likely can’t tell you is what you would see if you were in the room. The brain does a lot of processing of its own.

I suppose it shows that the LED has similar color characteristics to incandescent.

Sure, the photo tells you that both would look very similar to your eye. It’s certainly not an worthless exercise to compare with photos, I think everyone knows what incandescent light bulbs look like.

Am I the only one who prefers the cool white/blue of CFLs?

I prefer white light over soft yellow light :)

I read something a while ago about different cultures, and their preferences for different kinds of light. I believe North Americans tend to like the soft yellow, while many Asian cultures are more comfortable with crisp white. Although, I grew up here, so I'm not sure where my preference comes from.

American (USA) here, much prefer the white lights. White seems to be easier to read under than the yellow.

I prefer soft yellow in most of the house and crisp white in the bathrooms and office. In bathrooms it allows you to see everything clearly (a good thing?) and in the office I find it keeps me alert.

My thoughts exactly. It depends on the room; yellow in living/dining, and white in bathroom/office.

I have a white CFL desklamp in my home office, and by a chair in the corner I have a yellow corner lamp (admittedly incandescent not LED).

I prefer to do casual reading/relaxing under yellow light ("mood lighting"), and work/bathroom under white light.

This may seem like a binary issue, but really it comes down to setting and personal preference for the light used therein.

"Find out what you want, and then learn to ask the right questions." - Tony Shalhoub, psychiatrist in 'How Do You Know' (random but memorable quote from the Paul Rudd romcom I relented to watch with my wife recently)

As a photographer, I find incandescent easier to white-balance than CFL, although there are other photogs who swear by florescent.

I prefer a light suited to the task.

Fluorescent are great in work/task areas (garage, kitchen and bath).

However, my wife hates CFLs. They are so dim. At least the first generation were. They were no were near as bright as their wattage claimed (as measured by our eyes anyway).

That's why we have regular fluorescent in garage, kitchen, etc.

Dim? The first CFLs I bought were blindingly bright. The one in my bedroom now is too dim.

I don't know if this is a consistency issue or if I just haven't paid attention to the ratings, but to say "they're too dim" overall is, I think, oversimplifying.

As I recall, the fluorescents I like best usually have color temperatures in the 4000K - 5500K range. Anything below 4000 is too yellow. The 6500K bulbs I don't like as much, though this may have more to do with their low CRI than the color temperature.

This is a useless comparison. What matters is whether the spectrum is filled out or not. It's easy to make an LED light with the same subjective color temperature as an incandescent, but which is really only emitting three wavelengths of light. This bulb will be missing most of the spectrum and it'll make colored objects look wrong.

human skin looks better the more tinted toward orange/red you get. warm tones also make rooms feel cozy.

Glad to see these are finally coming into mass retail. I think they may have missed an opportunity to make the colour output somewhat customizable. They could have included multiple plastic covers instead of only the yellow one.

That would probably add more expense than it's worth. The yellow part isn't just a plastic color filter, the lights use what's called a "remote phosphor", where it's internally using high powered blue LEDs, which is then absorbed and reemitted in a wider spectrum at the yellow layer.

There are a number of reasons for doing this, but the biggest ones are that it gives it a large and more diffuse emitting area, preventing the multiple shadows from exposed LEDs, and (IIRC) that the phosphors tend to be more stable when not integrated into the LED.

$40, though, really?

Worth it, stretched over like 7 years?

The LED's should last alot longer than that. The problem is going to be the switch-mode power supply. I'd hold off on these things until their price drops a bit, and until we have an idea how long the PS will last. Has anyone done a teardown on these yet?

The CFL's I've bought from Costco are lasting less than a year for me, so I'm reluctant to start using them until they have the bugs worked out.

Here you go: http://www.edn.com/blog/PowerSource/40512-Remote_Phosphors_P...

Doesn't look like a high quality circuit to me.

Maybe it is the photo quality, but that main board looks almost hand-soldered instead of reflowed. The blobs on the SMT parts aren't consistent, although that may be because they have a mixture of through-hole parts so close.

My thoughts exactly. It looks like something that I would build by hand (messy) as opposed to something that comes out of a factory. I guess it doesn't necessarily mean that it will be unreliable, but I can't help but think so.

All would be forgiven if it wasn't $40. I was going to get a bunch of these, but at this price point it just doesn't make sense.

"All would be forgiven if it wasn't $40."

Early days.

That board is wave soldered, not reflowed. The through-hole parts are inserted from the top, the SMT parts are glued down to the bottom, then the bottom of the board is dipped in a fountain ("wave") of molten solder. The solder blobs are normal for wave soldering followed by hand soldering of the wires. Production costs can be very low, you just have to select SMT parts that can take the heat and thermal shock.

Less than a year? That's really short. Have you tried busting out a multimeter on your wiring (since you sound like the DIY type) or calling an electrician?

As long as it actually lasts that long (or has a credible guarantee) -- I've had plenty of CFL bulbs die within a year or less, which has made me wary of these sorts of amortized cost calculations.

Over a CFL for sure. This is dimmable, easier on the eyes (in my opinion), and doesn't have toxic mercury.

I see these have a yellow filter on the outside. That means they're throwing away light to get the right color. I think that's nuts, considering how hard it is to get that much light out of LEDs to begin with. I hope they make a version without the filter.

My understanding is that it's not so much a filter as a retransmitter layer. The LEDs give off a rather small spectrum of light that's quite harsh and the yellow "filter" takes that energy in and fluoresces out of a wide variety of wavelengths of light that are much more pleasant. There's most certainly a loss of energy because of the conversion, but it's not filtering out wavelengths like normal light filters do.

This is similar to what fluorescent lights do. If you've ever broken a fluorescent bulb, you'll notice a powdery coating on the inside of the glass, which is the phosphor coating that actually absorbs the violet/ultra-violet light of the excited mercury vapor and then re-emits it as visible light.

Looking forward to the Switch company's LED bulbs. http://switchlightbulbs.com/

This was mentioned on HN a few weeks ago.

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