LED luminaire review

February 25, 2010 at 12:24 am (Lamp reviews, LED)

After seeing it on the Northern Light Fair I wanted to test one of Lampkonsulenten‘s floor spot luminaires with warm-white high-quality LED in a home setting, as a reading/bed light.

Info: Price around 1 500 euro. Expected lamp life around 50 000 hrs.

Impression: Compared with an equivalent halogen floor spot of similar model, it actually lit up the pages of a book better and enhanced the contrast. LED light is very directional and this was no exception so it really focused all light on the book. However, when trying it for mood lighting it did not sparkle and spread the light around the room like the halogen lamp; the light sort of faded mid-air. When used as sole illumination, it made the room look a bit cool, dead and gloomy.

From these observations I draw the following conclusions:

1. A bit of incandescent/halogen light is clearly needed in order to create a warm and alive feel to the room. LEDs should thus be used as complementary light for specific tasks, or for decoration, not as primary light source.

2. LED is by nature a directional light source and should be used as such. Trying to get it to spread light in all directions like a standard bulb will just scatter the light so that the bulb illuminates little more than itself.

3. LED light is best utilised at fairly close range when using it for illumination.

4. Warm-white LEDs may need to have an even lower correlated colour temperature than incandescent lamps in order to appear as warm.

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Northern Light Fair

February 14, 2010 at 12:58 pm (Lamp reviews)
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Yesterday I was at the Northern Light Fair in Stockholm to check out the latest lamps.

CFLs

I have to say I was pleasantly surprised by most CFLs displayed. Both Osram, Megaman and italian Leuci had CFLs in good incandescent-like colour, looking decently bright too.

One of Osram’s displays. The lamps left and middle are CFLs, and the 5 to the right are decorative incandescent (which looked brighter in real life).

LEDs

While the LEDs certainly have improved since my last visit to the Light Fair two years ago, there are still huge quality differences between different types of LEDs.

First I checked out the holiday lights; strings, icicles, candelabras etc.

As usual, coloured ones were great, the cool-white horrid, and the warm-white ones of varying quality. Some were pink-white, others ugly yellow, but a few were actually very incandescent-looking, so clearly they are improving. However, only in light colour, not in light output.

In this picture the difference between the somewhat pale LEDs (to the left) and the glowing traditional incandescent strings (to the right) is clearly visible, even though it is clearer in real life.

Strings with many little light points still work as decorative lights, but in the candelabras there wasn’t enough light to radiate outwards, just a dull and gloomy glow inside the little bulbs, clearly not nearly as bright as the incandescent candelabra next to it and not at all giving that warm Christmas feel that you want from an electric candelabra.

In this picture the real incandescent candelabra is the glowing one in the lower left corner. The duller ones that don’t radiate are LED.

Next, I looked at non-decorative LEDs. Again I found great quality variations in the various attempts at producing bright warm-white light. I was not impressed with any of the LED retrofit bulbs from Osram, Megaman and Leuci. Bleak light, colour not quite right, still insisting on the less-than-great idea of putting LEDs in a retrofit bulb etc.

The best LEDs came integrated in luminaires from Norwegian luminaire company Lampkonsulenten. Their high power LEDs were of a completely different quality class and came in white and warm-white light which both looked decently incandescent-like and decently bright and radiating (as far as I was able to tell in this well-lit commercial setting; I’d have to try one at home to see if this impression holds). Compared to these quality LEDs, all others on the fair looked like a joke. But it made me a bit more optimistic regarding the options available for professional lighting designers even if their output is still limited and the quality not quite as high as real incandescent light. But I think they would do well compared with metal halide for example, at least quality-wise.

Halogen

Both Osram and Leuci had excellent halogen energy savers. The Osram representative said it is technically possible to make halogen lamps much more effective even without the integrated low-voltage transformer (which Philips use for their B-class halogen lamps) but it requires more R&D so they want to be sure there is enough market for it before investing and didn’t seem in a hurry to do so before EU bans C-class lamps in 2016.

So do let them know if you’re interested in even more effective halogen lamps now! If you like real incandescent light, this is the replacement to go for.

Luminaires

On the luminaire side, I found a great variety and much creativity. General trend seems to be softer shapes compared to the cold, hard designs that totally dominated the market just a couple of years ago, fewer black lamp shades (finally!) and much playfulness, e.g. integrating decorative LEDs in the design, using new materials in creative combinations, and making crystal chandeliers that truly look like something from this century.

Just a brief example.

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White LED Reviews

January 11, 2010 at 9:22 am (Lamp reviews, LED)
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Here I’ll review LEDs as I find them. The last two at the bottom are new for today. (Prices include 20% VAT and may vary between countries.)

* 1.2W Anslut ‘warm-white’ GU10 20-point reflector lamp

Info: 20-diode spotlight. Price was decent for an LED, just over 6€.

Impression: Don’t quite know what to make of this one. On the one hand it’s impressive to get so much light – at least in one direction – out of what is only 1.2W!

I picked this particular lamp because the light looked more white than the markedly green-white or blue-white I’d seen previously. It seems to have decent colour rendering too, both to the naked eye and in my DVD-test where I could see the full spectrum reflected without any large visible gaps (though no magenta).

Colour: Still slightly green-yellow-white (which is not surprising as ‘warm-white’ LEDs usually consist of blue diodes with yellow filters). Some may like this slightly cooler light (around 3000K, but gets a little warmer over time) but for my personal taste it still looks too much like FL light and gives my kitchen an industrial feel which dos not complement the warm colours and traditional design in a good way.

I have to say I was disappointed as I prefer mercury-free LED before CFL and would love to find a good enough LED to recommend instead. For commercial purposes fine, but not for home lighting unless that industrial feel is what you prefer. I’ll keep looking.

* 1.8W Kjell & Co ‘warm-white’ frosted E27 mini globe

Info: Price around 12€.

Impression: This lamp is a joke. It’s not even remotely warm-white, it’s cool-white like a moon-beam, and about as dim. It gives only 65 lumen, less than a 10W incandescent, which is good for absolutely nothing. You certainly can’t read in it and it’s not warm enough to be used as mood-lighting (except at a Halloween party perahps). And this was the brightest LED globe light I could find in Stockholm retail stores!

Looking at the small print on the back of the package it says this lamp type is recommended “for decoration” or “for dark spaces like the cellar stairs, the attic passage-way, the garage or storage area”. But it is not decorative, just dim and generally gloomy, now why would anyone want to put such a light in their cellar stairs and risk breaking their neck, or in spaces that are usually already creepy enough without adding a dim ghost light to it?

The only reasonable application would be as night light, but as this bulb requires a real luminaire with a full E27-socket, which makes it useless as night light too. (Instead, see my Coloured LED Reviews for a really great LED plug-in nightlight that costs only slightly more.)

* 4W clear ‘warm-white’ SMD E27 mini globe

Info: Price around 19€. Rated life 50 000 hours. 350 lumen or “about as much light as a 40W incandescent but using 1/10th the energy”. Will not get warm, light up 100% in half a second.

Impression: Yes, like all LEDs it lights up instantly and is luke-warm enough to touch even after being on for a while.

Colour: Warm-pink-white that looks similar to ‘warm-white’ fluorescent light rather than to golden-white incandescent light.

Brightness: Nowhere near that of a 40W incandescent. The 350 lm may be correct but a 40W incandescent gives 410-505 lumen and visual comparison between an incandescent 40W lamp seems to confirm it, so this seems to be another case of consumer fraud.

At the same time it is too glaring to the naked eye and must be used in a lamp with a thick shade so that the glaring little dots don’t shine through. Which reduces its brightness even more as it is designed to throw light to the sides rather than downwards. Tried it in different luminaires. In modern table- & floor luminaires it doesn’t work very well: what little light that finds its way out of the shade is very dim and gloomy indeed, and of no use whatsoever. A classic architect luminaire seems to be the only one it works with. The wide shade spreads the light much better than the very directional GU10 spotlight. In this luminaire it reading works if you can ignore the faint light dots reflected on the page.

Light quality: Like the other LEDs, the spectrum of this one is continuous in the warm end of the spectrum but spiky in the blue end, with no magenta. Colour in the room look sort of dampend, as if seen through a grey filter. Whatever room I try it in, it turns all gloomy and depressing. No life.

* 3W Cree ‘warm-white’ frosted E14 mini globe

Info: Price around 24€. 120 lumen or equivalent of a 25W incandescent. 50 000 hr life. Ceramic foot and chromed aluminium house.

Impression: The frosted glass makes this one easier on the eyes and works well enough to read in. The socket limits its usefulness as its long heat sink makes it stick out too far in all the various E14 reflector luminaires I have. Putting it in a luminaire with a shade will reduce light output too much. The best fit would probably be in a vanity light for those who want a non-glaring white.

Colour: Cool-pink-white. More like fluorescent light and even less incandescent-like than the Osram CFL tested above.

Brightness: Again erroneous equivalence info. An 25W incandescent lamp gives 215-235 lm so a 120 lm should not be enough to replace it. However, this one actually seems even brighter than a 25W incandescent, though the light itself has a duller quality.

Light quality: Continuous spectrum but with green, violet and magenta missing. Colours in the room tend to look a bit grey and faded and white surfaces look distinctly cool-pink, even though the bulb itself looks more neutral-white.

* 2W Osram Parathom ‘warm-white’ clear E27 Classic A

No picture but it looks like a normal size version of the mini globe above (= diodes on a stick stuck in a clear bulb).

Info: Price around 16€. For in- and outdoor use. 25 years claimed life.

Impression: Another useless LED. Very dim light, good for nothing. What Osram calls ‘warm-white’ is green-white. Even putting a peach shade on it does not remove the green tint. Not pleasant or attractive! Complete waste of money if you ask me.

I hope we don’t have to wait another two decades before Osram gets their WLED phosphor mix right.

* 3W Cree ‘warm-white’ GU10 1-point spotlight

Info: Price around 23€. 1-point spotlight with 60 degree beam angle.

Impression: Fairly bright for only 3 watts. This one too had green-white light. Not nearly good enough to replace my GU10 halogen spot.

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CFL Reviews

January 11, 2010 at 8:55 am (Lamp reviews)
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Splitting up my review of various energy saving retrofit lamps as I test them in a home environment. This post will focus on compact fluorescent lamps. The first lamp review is moved from my original post, the second is new for today. (Prices include 20% VAT and may vary between countries.)

* 7W Osram Duluxstar ‘warm-white’ E14 frosted CFL mini globe

Info: Appearance-wise, one of the most incandescent-like CFLs on the market, with a correlated colour temperature (CCT) at 2700K. CRI around 80 = standard (mediocre) colour rendering capacity. Price: about €10, but if you want a decent-looking (and decent-performing) CFL, be prepared to pay for it.

Impression: Visually, the light looked very soft and incandescent-like in the shop, but at home it still has a touch of that pink shade typical of flourescent light, though less markedly so than its early predecessors, more warm-pink than cool-pink, and admittedly an improvement compared with older CFLs and all the cheap budget lamps on the market.

Size-wise it only fit in one of my reflector luminaires.

As for colour rendering capacity, my do-it-yourself-spectral analysis with the back of a DVD shows the spectrum cut up into distinct bands with all the wavelenghts inbetween missing, as is normal for standard-quality FL light.

It does look bright enough to replace the promised 40W bulb (now in the beginning, will fade with age) though it took several minutes to reach full output. And the light was actually nicest before it did. Now it has turned a little more pink-white and makes the room look uniform and sterile. Many may not notice that much of a difference from an incandescent, or care if they did. But as I have a very well-developed sensitivty to such nuances, I could not relax in such a light and would never use it in my home.

* 8W Osram Duluxstar Mini Twist ‘warm-white’ E14 spiral CFL

Info: Correlated colour temperature (CCT) 2500K (“warm comfort light”). CRI around 80 = standard (mediocre) colour rendering capacity. Light flow: 470 lumen. Price: about €6. Made in China.

Impression: With even warmer light (= lower CCT) this one actually looks very much like incandescent light colour-wise = more golden than pink. Still a bit flat due to the lower CRI but definitely the best incandescent-copy I’ve seen so far.

Size-wise it is too big for all my different reflector luminaires, even though this is the most compact spiral CFL model I’ve seen. I can screw it in just fine but half of it sticks out. The part that is visible is very glaring. Calling my bf:s attention to the experiment, his first response was a loud “ouch” as the glare pierced his eye, and I got a dark afterimage in my visual field for several minutes afterwards from looking at it just briefly. I’d recommend it only in luminaires with shades.

Brightness seemed OK too. 470 lumen is even a bit more than the equivalent 40W incandescent (410 lm) with margin for the eventual light loss.

Nice job, Osram! Only took 2 decades to finally get it (almost) right.


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Coloured LED reviews

July 30, 2009 at 11:16 pm (Lamp reviews, LAMPS, LED)
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Here I’ll be reviewing coloured LED lamps.

* 1.1W Osram Lunetta Colormix LED night-light

Info: Plugs right into the electric socket and has a little button at the bulb base: each new click gives light blue, hot pink, cool green, soft orange, bright blue, alternating and no light. Also has a light sensor and turns itself off in the daytime or when ambient light is bright enough. Rather sophisticated for being the size of a golf-ball and will probably last ‘forever’. Price about 15€.

Impression: Love this one! LED technology used for what it does best: produce coloured decorative/lead light at extremely low wattage and heat loss. Is hardly even warm when you touch it. Great for kids!

* 3W unknown brand RGB E27 LED

Info: Remote-controlled LED retrofit lamp that can replace a standard bulb. Light output 140 lumen. Price about 36€ (incl shipping).

Impression: I wanted to know a) if I could get a more natural looking warm-white by tuning it myself and b) if I’d be able to create any shade imaginable. The answer to both is “no”. a) The white is nowhere near white, but a visible mix of different colours. b) The 16 colours are pre-set and cannot be adjusted manually as I had mistakenly assumed. A home spectral test with a DVD shows the blue-green part of the spectrum very clearly, then a dip in the yellow-orange area, then a nice bright red and no magenta. Lighting food and clothes with it made red bell peppers and a blue robe look almost fluorescent.

But what did I think of it otherwise? Well, the truth is that I love it anyway! What is probably an unintentional design flaw – that in mixed colours it shows the mixing colours separated into concentric rings instead of being displayed as a smooth blend – actually makes its light beam uniquely special, intriguing and pretty, as long as one does not need a white light to see well in. It’s purely decorative, but very much so!

This is what its beam looks like on my pebble-patterned desk:


* 7W Philips Living Colors RGB LED


Info: Remote-controlled indirect floodlight that puts colour on a white wall. It does what I thought the simple RGB lamp would do: with the remote control it is possible to choose any hue by scrolling on the colour circle, and fine-tune both colour saturation (from deep to pastel) and light intensity (from bright to dim) to the desired shade. Price about 150€. Also comes in a mini-model for around 100€.

Impression: I’m fairly impressed with this one. Very cool futuristic design: a decorative object in itself. Almost the size of a soccer-ball (though more resembling a small gold-fish bowl with a goth vase in it). Nicely designed and easy-to-use remote as well.

Great light for mood & decorative purposes. Not sure about the “16 million colours” – that’s probably more theoretical than practically achievable – but it seems to have enough versatility to let one create one’s favorite hue and shade fairly exactly. Except a good white, just various pastel tints (which are nice in themselves, though not perfectly white).

I’ll give it 4½ lightbulbs out of 5. One of the most fun and versatile lighting products I’ve ever seen! I especially like the possibility of creating pastels, as they make the room brighter and create a softer and more sophisticated lightscape. I’m finding that I can easily change it to match the dawn outside my window as it gets brighter and sunnier.

Example of how the beam looks on my (unfortunately not flat) white wall when I tune it from softest pink to brightest red:




YouTube has some videos of varying quality of how it looks while shifting colours:

Update 1 Aug: After using it as general lighting in my home office for a couple of days instead of my halogen two-way desk-light, I find that it has an odd side-effect on my vision. Directly after using it and turning it off, all natural light looks strange and ‘fluorescent-like’ for a while until my eyes have readjusted to normal lighting. I’ve noticed this with the other RGB LED as well. This does not happen even after a whole day staring at my CRT screen.

Update 4 Aug: I first thought the explanation might be the odd spectral distribution unique to LED in general, but it’s probably as simple as the light in the RGB LEDs being coloured and hyperstimulating the cones. After using the warm-white GU10 LED spotlight as desk lighting for a day, I do not get this effect.

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Halogen Energy Saver Reviews

June 9, 2009 at 8:57 am (Halogen, Lamp reviews)
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Here are reviews of retrofit halogen energy savers. Brief descriptions + my personal, subjective impressions of how they look in my home environment. (Note: prices are converted from SEK to Euro, include 20% VAT and may vary between countries.)

* 28W Osram E27 clear A-lamp

Info: CRI 100 (= full colour rendering). Costs about twice as much than its incandescent equivalent, uses about 20% less energy (though advertised as 30% less) and lasts twice as long.

Impression: Looks exactly like the 40W incandescent equivalent it’s supposed to replace, though slightly brighter and with a rather glaring light point so best for luminaires with a shade.

* 28W Osram Spot R50 E14 reflector lamp

Info: CRI 100. Costs only slightly more than its incandescent equivalent, uses 20-30% less energy and lasts twice as long. 

Impression: Looks exactly like the 40W incandescent it’s supposed to replace. And when I say “exactly”, that means exactly and not “more or less similar”, since halogen is an incandescent light, only concentrated into a smaller inner bulb.

* 30W Philips Master Classic E27 frosted A-bulb with infra-red coating and integrated transformer

Info: A low-voltage retrofit lamp that can be used in a standard mains-voltage luminaire. CRI 100. Costs over 10 times as much (€13) due to the built-in electronics, but then it lasts 3000 hours, so divide that by 3 and then deduct the 50% electricity savings and it’s not so bad.

Impression: This one too gave a nice warm-white incandescent light that looked bright enough to replace a 60W bulb, as it promised. I could not tell it apart from a standard 60W frosted bulb.

Update Dec 2011: I’ve not used this one very much at all, just as a desk light on those few occasions when I’ve worked on something not on the computer. Yet one day a few weeks ago it just died. I have definitely not used it anything close to 3000 hours. And this is the only type of incandescent bulb that will be permitted in the future, if the European Commission doesn’t change its mind. (OK, one bulb does not make a proper consumer test, I could just have been unlucky.)

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More lamp descriptions can be found on this site: http://lightbulbmarket.blogspot.com/

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