Buying a light bulb used to be easy

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Buying a light bulb used to be really easy, but that changed with the arrival of energy-saving models.

It is very hard to buy a quality light bulb. I have often bought from "good" brand-names and got disappointed.

Here is a feature list:

  • Brightness.
    Unfortunately, the lumen values are not linear (they do not increase proportional to the current flow), especially from 2,000 Lumen. I don't know the maths. If you can help, please drop me a line. This is the table I have been using for reference:
Incasdencent Watt Lumen LED Watt Energy-saver Watt Halogen Watt Info source
40 W 450 lm 5 W 10 W 1
60 W 800 lm 10 W 15 W 1
75 W 1100 lm 14 W 20 W 1
100 W 1,200 lm
150 W 1,700 lm
1,900 lm 23 W
2,700 lm 28 W
2,800 lm 30 W
3,000-3,250 lm 160 W
200 W 10,000 lm

Info source 1: El País, La (ardua) tarea de elegir la bombilla perfecta y ahorrar.

  • Color temperature.
    2700K is best for ambient light. It yields a yellowish light comparable to the traditional incasdencent light bulbs with a tungsten (wolfram) filament.
    3000K might be described as "soft, warm white", but it's a little too cold and you'll notice the difference. It is best for colour visibility at the workbench.
    Anything over 3000K will be too cold, and the light will turn blueish.
  • Turn-on speed.
  • Lifespan.
  • Cycling endurance.
  • Clear or frosted glass.
  • Noise.
  • Dimmable.
  • Physical robustness.
  • Operating temperature.

Compact fluorescent lamp (CFL)

I am particulary dissatisfied with compact fluorescent lamp (CFL) technology, especially after all the hype.

Its many drawbacks are:

  • Expensive.
  • Slow to turn on.
  • Often last much shorter als advertised, due to low cycling endurance.
  • Noisy. Most CFLs make a humming noise that you may notice in a quiet environment.
  • Cold light colour.
  • Normally not dimmable.
  • The light bulb itself is also ugly.
  • Contain toxic mercury (quicksilver) which complicates their disposal.
  • They turn darker with time.

On the bright side, they consume very little electricity.

LED lamp

LED lamps have a few drawbacks:

  • Expensive.
  • Weak. I just cannot find powerful LED lamps. The ones I see around are too weak for the living room.

They win in every other category.

Halogen lamps

Halogen lamps usually have a colour temperature of 3000 K, which allows you to see colours properly. Therefore, these lamps are suited for desk lamps or spot lights for workbenches or the kitchen area where you do food preparation.


  • Cheap.
  • Fast to turn on.
  • Bright.
  • Good colour visibility.


  • High electricity consumption compared to CFLs or LEDs.
  • They lose a lot of brightness with age (see 'cooking' below).
  • Dimmable, but you often get a hummy noise when dimmed from the power supply.
  • They get very hot, so:
    • They tend to turn darker (they 'cook') with time.
    • If you touch one during operation, you'll get burnt.
    • Careful when cold too. Fingertip oil may make them even hotter and damage them.
  • Some halogen bulbs shed a cold light (colour temp 3000 K or higher).

Fluorescent tubes


  • Cheap.
  • Powerful.
  • Consume little electricity.


  • Big, long.
  • The starters break down often.
  • Cold colour.
  • Slow to turn on.
  • Poor cycling endurance.
  • Humming noise.
  • Not dimmable.
  • Brittle.