LED: 2500K is the new 2700K

Singapore, 24th July 2014

Something that has been bugging our team for a long time is the notion that incandescent light colour has to be 2700K. While manufacturers have been improving day by day in getting us good colour consistency we have been plagued by visual feelings that the 2700K colour temperature that has been the benchmark for the colour of incandescent light, really does not feel that warm when it comes to LED. We find that LED in 2700K feels like 3000K and that LED 3000K really feels like 3500K or thereabouts. We have found this time and again when inspecting completed lighting installations.

So over the last couple of months we have embarked on some search and test missions to get the better of our frustrations. We had another such test yesterday with a specific lamp manufacturer and tested what is being marketed as 2700K as well as 2500K and 2200K. As it appears manufacturers are also coming to grips that in LED technology 2700K does not look that warm and you will have noticed the 25000K and 2200K lamps appearing on the market.

I, for now, am convinced that if we need warm light for LED to produce a  matching feeling to incandescent lamps we need to specify 2500K maximum and in some cases even 2200K. The visual impression is overwhelming and very convincing. We are continuing our research and testing with other manufacturers but our findings so far are quite conclusive. While down lights may still work reasonably well with 2700K temperatures, when it comes to table, floor or wall lamps we will now use 2500K and when it comes to pendants and chandeliers even 2200K to get that nice warm feel.

With the same process we are investigating the use of clear and frosted LED bulbs as some applications like chandeliers need that sparkle. Different LED technologies also create different brightness patterns in light bulbs. Do you want a diffuse looking light bulb or do you want a frosted bulb with a clear hotspot. Supporters will argue this is reminiscent of the filament…Oh, if only life in lighting would be simple… 🙂

Light watch 5-122: The pictures of the testing may not be as convincing as a photo does not capture things like our eye does, but I think these series of pictures says it all.

2700K vs 2500K

2700-2500K comparison

2200K vs 2500K

2200 vs 2500K

2200K 2700K 2500K compared

2200 2700 2500K

SMD(base) vs COB LED (centre)

different LED technology SMD vs COB ctr

LED clear vs frosted

clear vs frosted glass


24. July 2014 by Martin Klaasen
Categories: Light & Learn, light watch, lighting and culture, lighting applications, lighting design, lighting standards | 17 comments

Comments (17)

  1. Yes, the lower K LED bulbs have a field of use. There is a bright scream in replacing street lighting with the lower K realm for less light pollution also. For indoor, the dimmable LEDs have caught attention.

  2. Where do you get 2200K 2500K LED bulbs? I can’t find them on the web. And if you can find them where can you find them in a dimmable version?

  3. Is it possible to get LED strip lights for cove lighting that approximate an incandescent look?

    Acolyte LED has a tunable 3-color LED strip that is very good but also very expensive and very complicated to use. It has three colors–white, warm white, and amber–that are manually dialed to get the desired mix.

    Maybe there is something like this in the U.K. or EU?

  4. bonjour Monsieur ,
    can you tell us address company
    to import in france lights for interior and exterior led 2200k 2500k and 2700k ?

  5. I knew it! I always thought those 2700K bulbs were very white. Maybe people have been mistaking low CRI for too-low color temperature? Alas, I’m not allowed less than 2700K according to Title 24. They can’t regulate my floor and table lamps, though.

  6. Thankyou Martin. What amazing insights! Complete with photos! Bookmarked.
    Yes, I agree 2.7 k is not all that warm subjectively. Fine in my day studio, but cosy bedside lamp it is not.

    B&Q have an own-brand ‘filament’ type bayonet LED which looked to be warmer, just, but two broke up internally almost immediately. Hunt is now on to find those elusive 2.2 or 2.5 you mention, in durable format, and at 75 or 100W equivalent.

    While here, I wonder if you’ll be addressing an alleged shortcoming of LED healthwise (Google Dr Mercola)? He says that our skin needs far infra red, and if we don’t get sunshine (UK!) or include some incandescent, we might be deprived. LED domestics don’t emit far infra red, do they? Would not be so energy efficient anyway.

  7. Has anyone found strip light bulbs with 2200k or 2500k? If so, where?

  8. Sorry, should have said that I am in UK.

  9. California Title 24 requires residential lighting to be equal to or less than 4000K for inseparate LED luminaires, GU-24 lamps, and LED light engines and 3000K or less for all other light sources. Also CRI of 90 or greater and R9 or 50 or greater is required. There is no restriction against 2200K, 2500K, etc. There is no restriction against using ANY LED in non-residential lighting. We have legally installed a lot of 2400K for the very reasons Martin describes. It is available in tape light and LED lamps, but very little elsewhere.

  10. @Phil Holton: we are able to get LED tape lights at 2400K easily online. Obviously Asian but with superb CRI (~94) and look warm and lovely like they should. I suspect that similar products are available in the UK. Available in both indoor and IP 54 versions, I think and in normal and high output.
    @Martin Klaasen: Spot on my friend. We are using 2700K a lot and there are many who prefer warmer. Testing 2400K and 2200K for street lighting now.

  11. Thank you for some good info in this article. I ventured into my own LED installation a little over 5 years ago. At first, most of what was available locally was 3000k, then 2700k a few months later. But, my house has a lot of antique and moderate earth tones used inside which was selected to go with incandescent service. It looked bad with 3000k: apparent hot spots were accentuated [hard to avoid in a hallway], and while it seemed I had more light… it also made spaces seem a little smaller to my eye with the loss of some visual softness. The comforting effect of the existing paint scheme was destroyed by 3000k [but its great to spot things when cleaning]. I went to 2700k and that was ok, but it’s still a touch whiter. Think I’ll try 2400k – 2500k indoors next which was unavailable to me at the time, and make outside access lighting 2200k for less annoying glare to neighbors [they really do notice].

  12. I agree. I used Cree high CRI 3000k PAR38s in a cathedral installation in which we replaced 100 watt HIR PARs. The light from the Crees turned out to be whiter than I would have liked (I would say it looks closer to 3200k) and it is not blending with the remaining halogens in service. I wish I had gone with 2700k.

  13. Thanks for the feedback!

  14. A project I’m working on lead me to this part of the Internet. In my search for bright 2200k – 2400k LED lighting. I ended up mixing the light from two separate led strips run in parallel. One being a fixed orange/amber color and the other being a 2600k – 2700k white strip. The application was under frosted glass which managed to keep the glow in check and resulted in the wood in the project taking on a warm natural but well lit glow that did not color the wood in a odd manner. We chose to add the additional white led strip due to the amber strips lack of brightness and it lacked the correct color temp to keep wood colors in check.

  15. Hi! I’m working on some lighting design and would love to get my hands on a tool like yours with the different LED bulbs to test different color temperatures. Do you know where I could purchase and order from? Thanks in advance!

  16. Hi Carla
    Best is to ask your suppliers. They would be able to help and depending on your projects they can provide you with the necessary samples. Seeing is believing, always! Certainly with LED. Test it, feel it, experience it! Cheers MK

  17. Every website compares 2700K LED bulbs to the color of incandescent bulbs, but it’s so obvious that the LED bulbs appear much colder (and unattractive) in comparison. Why are the manufacturers maintaining this fiction? And when will we see a selection of 2200K and 2500K LED bulbs?

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