The Light Fantastic

Thomas Edison perfected the first incandescent light bulb in 1879. It burned for 13.5 hours. And incandescent bulbs are still burning 131 years later, but at a price that’s costly to both our wallets and the environment. Incandescents are extremely inefficient. They operate at about 20 percent efficiency with the other 80 percent given off as heat energy. And an incandescent light bulb’s average lifespan is only around 5,000 hours or roughly one year.

But while incandescents are looking more and more like the has-beens of light bulbs, light-emitting diodes, or LEDs, could be the future. LED bulbs are more efficient, less costly in the long run, and better for the environment because they use far less energy than the alternatives.

An LED bulb’s lifespan is around 50,000 hours, or about 10 years, which means it lasts 10 times longer than an incandescent bulb. Its upfront cost is more expensive, but the longer lifespan means less money spent on replacing bulbs, fewer operating and maintenance costs from replacements, and less waste piling up in landfills across the country.

But most importantly, LED bulbs realize 80 percent efficiency and only give off 20 percent of their energy as heat. So simply put, LED light bulbs use less energy, and the energy that they do use is put to more efficient use. The potential to reduce our total energy consumption with LEDs””from single-family homes to the illumination of whole buildings””is enormous.

They’re also becoming easier to find. So easy, in fact, that you can find LED lights all over the Internet and even in stores like Home Depot. This month Home Depot will start selling several types of LED light bulbs in stores and online for less than $20 in an effort to get people to use more LED lighting. Perhaps $20 doesn’t seem cheap to you, but imagine if that one bulb lasts for 10 years.

LEDs are already a large part of daily life. They are found in digital clock numbers, remote controls, Christmas lights, and are even used together in some traffic lights. Implementing their use on a grander scale could have extremely positive effects.

Take Pittsburgh, for example. The city is considering replacing 40,000 high-pressure sodium lamp streetlights with LED streetlights. This energy-efficient move would save $1 million in energy costs, $700,000 in maintenance, and reduce carbon dioxide emissions by 6,818 tons.

The price of LEDs is a barrier to their wider use, but prices seem to be decreasing faster than expected. Until recently, most experts didn’t think LED light bulbs (one equivalent to a 40-watt incandescent bulb) would be priced under $30 until after 2012. Luckily, they were wrong. (2012 is also the year that federal legislation bans the manufacturing of some forms of incandescent light bulbs in the states, and by 2014 most incandescent bulbs will be discontinued, furthering the purpose of LED lights.)

If the price of LEDs is still a hurdle for you, compact florescent lamps, or CFLs, are a cheaper alternative that are also much more efficient than incandescent bulbs.

Increasing LED light use in your home, at the office, or on the streets of your hometown can help reduce energy use and emissions (they also don’t contain mercury“”another environmental advantage). So don’t hesitate to grab a friend or a neighbor and let them know about LED lighting’s green benefits. Go forth to share the knowledge and spread the light.

— This is a CAP cross-post.

I debunked the Economist’s nonsensical piece on efficient lighting here:  Efficiency lives “” the rebound effect, not so much: Shining some light on bad analysis in The Economist

51 Responses to The Light Fantastic

  1. NeilT says:

    I don’t mind the price but they have to do the job. Something CFL’s don’t! I moved into an apartment in Stockholm during the week for work. During the summer it’s been fine, I’ve had plenty of light from outside and lighting was not a major issue. Apart from not being able to see much of anything in the kitchen or the bathroom that is.

    However winter is drawing in. Good lighting is vitally important and CFL’s are, quite simply, useless.

    I finally found 70 watt halogens which throw similar light output to 100 watt indandescents. That has helped a lot. But I can’t find any with micro edisson screw fittings so I’ve had to buy 3 11 Watt CFL bulbs for the living room. OK it’s better than the 40 watt incandescents that were in there, but it’s hardly what I would call reading light.

    In the long run I’m probably going to have to buy 1 or two 300w halogen uplighters as the ONLY way of getting reasonable light in the apartment during the long winter lights.

    So that’s 3 11 watt (supposedly 210watt incandescent equivalent), CFL bulbs, two 70 watt halogens in the lamp behind my desk and over the settee for reading and one or more 300 watt halogens.

    All so that I can replace the light I would have got from 3x 100 watt incandescents.

    So when they talk about LED lights, they need 100 and 150 watt incandescent equivalents or it simply won’t fly and people won’t buy them.

    It doesn’t matter if they cost $40 if they are going to last 10 years. It DOES matter if they don’t throw decent light.

    I have enought issues with deniers/disinformers claiming our political elite are using the climate issue to throw us back into an age of candlelight, without having the products actually looking like they’re candlelight…….

  2. Heraclitus says:

    The Economist had a recent article in their science section suggesting that more efficient lighting would increase energy consumption – demand will increase so much that the energy saving would be cancelled out.

    They may, or may not, have a point, but this underlines the importance of making changes based on environmental awareness rather than economic expedience.

    [JR: They don’t have a point, as CP showed here.]

  3. Heraclitus says:

    NeilT – you might benefit from reading the Economist article:

    “It is worth remembering that when gas lights replaced candles and oil lamps in the 19th century, some newspapers reported that they were “glaring” and “dazzling white”. In fact, a gas jet of the time gave off about as much light as a 25 watt incandescent bulb does today. To modern eyes, that is well on the dim side.”

    Perception is everything.

  4. NeilT says:

    Perception may be everything, but I still have 100 watt incandescent bulbs at home. When I want to remind myself what good light was like I go home and switch them on.

    My wife is so adamant that CFL’s don’t prvide good light that she won’t let me buy them. Although it has become almost impossible (but not impossible), to get good wattage incandescents.

    I use a 40 watt neon for my office at home. I’ts 4 foot long and supposed to be for a large room. It just does. The downstairs kitchen has 3 40 watt Neons. Then again I’d need 3 incandescents in it anyway so it’s about the same.

    The point I’m trying to make is that it is easier to get people to take up new technology if they don’t also get a degradation in the quality of the product (light).

    Gas took over from Candles because it produced more light, was low maintenance and was (relatively) clean compared to smoky candles which needed replacing and the melted wax cleaned out, daily.

  5. Robert Brulle says:

    The LED technology has really advanced. I went to Home Depot and replaced the 3 halogen lights on my desk. Instead of using 150 watts (which made me not use the lights very often), I now use 9 watts and get the same amount of light. So that is over a 90% reduction in electricity use. Sure, the bulbs weren’t cheap. But they will pay for themselves over time.

    One problem – the Phillips bulbs I bought at Home Depot were made in China.

    Can’t we have a renewable energy industry in the U.S.???

  6. ToniM says:

    In my life, I’ve used incandescents, halogens, oil lamps, florescents, and CFLs to read by. When I found out they were phasing out the production of incandescent bulbs, I went and bought enough to last me forever in my reading lamp. It’s not only the light output of the bulb, it’s the color of the light.

  7. mark says:

    Compact fluorescents don’t like dimmer switches. How do LEDs fare?

  8. Heraclitus says:

    People whining about having to change their lights always makes me despair. If we can’t accept even this minute reduction in the comfort of our lives then we haven’t a chance. All lights in our house are CFL and we cope just fine. We all read. We all do work. It’s just not that bad. What’s more this makes a significant difference. Domestic lighting is a meaningful chunk of global energy consumption.

  9. darth says:

    The Economist article that was linked in #3 is ridiculous. It’s conclusion has already been demolished by comments over there.

    NeilT – An 11w CFL is only equivalent to about 65w incandescent – you need to get 15w ones, they are much brighter.

    You use neon lights in your house? I’ve never heard of that. Where do you buy them?

  10. Bob Wallace says:

    Neil – sounds like you need to try a higher wattage CFL. You can get, for example, a 42 watt CFL that has the measured light (lumens) output of a 150 watt incandescent. One company makes a 65 watt CFL which has the measured output of a 300 watt incandescent.

    Toni – CFLs come in many different ‘colors’. If you want your reading lamp to be about the same color as you would get from an incandescent bulb you need to look for a CFL with a “Correlated Color Temperature” in the 2700K to 2900K range.

    Mark – Most CFLs do not work with dimmers, but there are CFLs on the market which do work with dimmers.

  11. NeilT says:

    @9 darth, I get the neons in the local DIY store. It’s in France but the same in the UK and most of Europe.

    They have diffusers on them so they’re OK in my office and the kitchen but I wouldn’t put them in any bedroom or living space.

    @10 Bob, I could have bought 15 watt CFL but they don’t sell them here with the mini screw fitings. In fact they normally sell 5 and 7 watt mini screw fittings here. I was lucky to get 11 watt. The bulbs are huge in comparison to the candle bulbs I took out.

    At home I have one 20 watt CFL bulb and can buy up to 35 (for about €50). But why bother? The light is garbage. I’m better off buying either full neon (as I have in my office) or industrial incandescents which give decent light.

    The point is I really want to buy into LED. I think it’s a brilliant idea and I’d like to get away from my neon lights.


    If the light they emit is anything like CFL there is no way I’m going to waste my time.

    Hence my comment. If the manufacturers are going to make them then they need to make equivalents.

    I looked at them at home in France two months ago. They have 1w, 2w and, holy of holies, 5w for €50.

    So, the article says LED’s are 80% efficient. That means I can buy 20w (equivalent) bulbs for €50 and then either buy 4 to replace a 100 watt bulb or squint.

    I decline.

    I know it’s the way to go, but this is not it. They have to have viable products that fit the market.

  12. I’m proud that Ann Arbor, MI, the home of my alma mater, has switched city street lights to LEDs.

  13. NeilT says:

    @8 Heraclitus

    When I still have to drive a car on petrol (OK my wife’s is diesel and much more efficient), then I refuse to worry about a few lights which are only on when it’s dark.

    Plus, in France I have a nuclear power station 30 miles away. In Stockholm I’m pretty sure their power is Nuclear too….

    I refuse to damage my eyes because manufacturers won’t deliver what we need. There is no excuse for it. Either supply viable products or don’t bother. Unenlightened consumers will never by them and there’s 1,000 of them (at least), for every one of us.

    I quite deliberately didn’t get into the environmental nightmare of CFL and dumping them as opposed to recycling.

    LED is the way to go. Now we need governments to invest in it so that we can get products people want to buy.

    It’s got to be better than funding ever increasing Coal fired power stations????

  14. Leif says:

    New kid on the block. Micro Plasma.

    I have not seen much new from this quarter in the last year and a half but I assume that they are still active. They have a very informative web page and efficiency surpasses LEDs. Light quality is also good.

    With regard to CFL, as pointed out by others already, there is a a big difference in light quality optimized for different wave lengths. I have inadvertently bought some types that have been unacceptable for indoor living and others that are just fine.

  15. Mike#22 says:

    NealT, true most CFLs are unacceptable for indoor lighting. The color is terrible. However, some lamps are very close to incandescents.

    I see that sells the GE energy smart cfls for 6 eur. Try a 20w in the 2700k color, I think you will find it acceptable.

    The color from halogens is perfect. The LEDs can easily match this quality (not the cheap off brand LED lamps made up of a bunch of little leds) but the cost is still a little high.

    For uplighting, try and find a t6 circline lamp with some good color. Two or three of those at 50 watts each should really light up a room.

  16. Antoni Jaume says:

    NeilT says:
    September 26, 2010 at 11:35 am
    “@9 darth, I get the neons in the local DIY store. It’s in France but the same in the UK and most of Europe.

    They have diffusers on them so they’re OK in my office and the kitchen but I wouldn’t put them in any bedroom or living space.”

    What is a neon to you? I find strange that you use them for common duty, particularly since you find CFL light unacceptable.

  17. NeilT says:

    @22 Mike, thanks for that. Sad that I have to go to Amazon though. Whilst they’ve all but removed incandescents from the market, in Europe, they haven’t ensured that the options available to replace them are viable for the majority of people.

  18. Some CFLs like their larger cousins strip fluorescent lights have sharp peaks of output in the colour spectrum often in the green frequency band. Photographers are used to this and once used compensating filters, and longer exposures which because of reciprocity failure when it occurred caused a further colour shift.

    Tungsten lighting, the normal incandescent lighting, has a fuller spectrum but with the peak concentrated towards the red end of the spectrum. In the days of film this also required the use of filters or a film balanced for tungsten lighting. What a blessing it is to be able to change the White Balance at the touch of a button, at least on my DSLRs with a range of + or – adjustments around a datum for each light source type.

    Colour films also had a tendency for separate peaks in each of the three primary colour bands of blue, green and red in a Spectral Sensitivity Curves chart, although with more gentle slopes than the sharp peaks in the similar for a fluorescent lamp output.

    It would be a good thing to press for light spectra information on the packaging. In the meantime a photographer’s colour meter may provide useful feedback, something I have never felt the need to indulge in because of cost.

    Also, an Englishman, Joseph Wilson Swan had a hand in developing the incandescent lamp.

    Finally, tungtan filament lamps once lasted much longer than those available post WW2. My grandmother had a lamp in her pantry (a store for groceries) which she alleged was fitted in the late 1920s when she altered what had been an internal coal bunker into said pantry, with a smart shellacked floor. This bulb finally expired in the late 1960s, about 1969/1970 having survived a bomb near miss and stray Me(Bf)110 cannon shells during WW2.

  19. On LED bulbs I have obtained and fitted such bulbs, with a ncessary adaptor into my large and small MAG-LITE hand torches (flashlights to you in the US), makes batteries last much, much longer per charge. I have some rechargeable alkalines that were available a few years ago made by RAYOVAC.

  20. RobLL says:

    We had a trained light person advise us when we built our house ten years ago. We use some 3 dozen 65 watt incandescent lights in cans, and almost all of them on dimmers. After ten years we still have not replaced half of the bulbs. We have replace a number of dimmers, they are beter now than then. We have another dozen regular incandescent lights which are used occasionally, and infrequently replaced. In our main living space/kitchen and over the dining table, where we spend much of our life is a 7 bulb (totalling about 300 watts) chandelier using regular bulbs, also on a dimmer. These get replaced regularly. I would not replace them with LEDs until I know I will like the color of the light AND the bulbs are guaranteed at least for five years. $350 to fill this fixture with lights that will be obsolete a few years later – not for me.

    We live in the Pacific Northwest, very cheap power rates, and the heating season is several months long, so the wasted heat really is not all that wasted. We do heat and cool our house with a 1 1/2 ton unit heat pump. Our size of house would have called for a 5-6 ton unit 20 years ago. Lots of thermal mass, insulation and good windowing (lots of them ) was the principle trick. And a free standing propane fireplace for the occasional very cold spells. We always have as much light as we need/want, but only turn on what we need.

  21. Berbalang says:

    We have pretty much replaced all the incandescents in the house with CFLs. There may be one or two incandescents in unused closet lights, but that’s it.

    I like the CFLs! I don’t have to climb on a chair to replace one every couple of weeks. If you get ones with a decent color temperature, you don’t notice the difference between them and incandescents.

    So far I have not been impressed with the LED bulbs. They have not been as dependable as advertised, not as bright as I was led to believe and expensive. The only place they have been of any use is in the front porch fixture outside. Cold weather doesn’t give them problems lighting.

    However, I do expect the LED bulbs to improve and will eventually switch to them.

  22. mike roddy says:

    People are confusing CFL’s with LED’s, which have far better lighting quality, and last a lot longer, too.

    We should switch to LED’s and make them code, but lights only account for 10-15% of building energy use. The real opportunity lies in reducing building heating and air conditioning energy use, America’s biggest single source of energy consumption and CO2 emission, far more than cars and factories. Much of it comes from coal plants.

    There are many ways to do it, even with retrofits. I suggest that you run a series of posts on this, Joe. It’s possible to retrofit a commercial building to be zero net, and I know an engineering firm that can do it. I can ask the CEO to author a post on it- his firm, PE Consulting, has saved clients over $2 billion in energy bills over the years. Besided neglected and existing technologies, many financial instruments, including in the tax code, are underutilized. I hope you read this and can comment and get in touch with me on it.

  23. Michael says:

    And an incandescent light bulb’s average lifespan is only around 5,000 hours or roughly one year.

    Most incandescent bulbs that I have seen are rated for only 750-1,500 hours, depending on wattage, except for those “long life bulbs” (rated at a higher voltage, which results in a longer life but lower efficiency) rated for up to 5,000; if that takes into account typical usage, so they are used for 20% of the time (4.8 hours per day, which would give the “5,000 hour” figure for an incandescent rated at 1,000 hours), then the LED bulbs would last for over 28 years.

    Also, as for CFLs having poor light output, I have them in my house and if you get the “good” ones, they don’t look any different from incandescents.

  24. Mark says:

    Mike Roddy,

    Agree completely that the majority of our energy is used to heat and cool our buildings.
    Thank you for the pointer to the commercial retrofit company.

    Do you have some similar pointers for people or organizations that have experience retrofitting a residential home to net zero or near net zero?

  25. Bob Wallace says:

    Lionel, just shoot RAW and don’t worry about setting the white balance while you’re shooting.

    I’m using Fast Stone (very good and free editor/viewer) for my casual RAW image viewing and find it does a good job setting the white balance automatically. For important shots I might tweak the setting a bit.

    LEDs are likely the lights of the future , but the price just isn’t there yet. Comparing the Home Depot bulb linked in the article LEDs just don’t save that much more energy.

    9 watt CFL. 400 lumens. 44 lumen/watt. ~$5 ($0.50 around here)

    9 watt Home Depot LED. 429 lumens. 48 lumens/watt. $18.47

    40 watt incandescent. 460 lumens. 12 lumens/watt.

    LEDs might make economic sense when lifetime is factored in. And if one really needs a dimmable light as dimmable CFLs are somewhat more expensive.

    And the mercury issue? Much to do about little. Most people have access to CFL recycling drop off sites these days. And how many people really break light bulbs?

  26. Anne van der Bom says:

    Every time the subject of CFL is brought up, it attracts a few stiff opponents. Personally, I have used CFL everywhere in my house since the beginning of the 90’s. Currently you can buy good ones that give off pleasant light, and I definitely don’t needs the same wattage in CFL as in incandescent as NeilT describes. But hey, that’s just me.

    I am puzzled by this for a longer time. How come, that some people are so adament that CFL’s do not give off 5x as much light per watt than incandescent, but perhaps something like 1.5x or 2x? It is hard for me to understand that they are just imagining, like some people think their headache is caused by their neighbour’s tv because it started when they got a new one. NeilT, just to be sure, you *did* wait 5 minutes for the CFL to heat up and attain full brightness, didn’t you?

    The only difference I can think of is that the spectrum of an incandescent light is continuous and that of a CFL composed of multiple, narrow emission bands. Could there be a biological reason that somehow their eyes happen to be less sensitive to these exact emission bands? That would also explain why they find the light unpleasant. Is there a doctor in the house that can answer this question?

  27. GFW says:

    We use CFLs. The standard spiral bulbs are pretty good, if a reliable brand is chosen – I like my GE 26w (100w equiv) lights quite well. But the CFL reflector bulbs for downlights (aka PAR30 bulbs) suck. Slow warm up, sometimes noisy…

    LED and Microplasma are good options for the future, but I think we need to rethink the shape of lights using those technologies. Why have a few concentrated spots when you could have large areas giving off a diffuse glow? That solves the heat-sink issue for LEDs, and would be a more pleasant light in my opinion.

    Finally, there’s another option, but it’s been much longer in development than the company initially promised. VU1
    It really sounds great, but they’d better hurry up.

  28. Anne van der Bom says:


    One of the reasons your incandescent bulbs last so long I guess is the fact that they are on dimmers. Reduce the brightness a bit and you will get a much longer life, but it comes at a price: an even lower efficiency.

    I guess the standard life of ~1000 hours for a regular bulb is a compromise between lifetime and efficiency. From Wikipedia:

    “a 5% reduction in operating voltage will more than double the life of the bulb, at the expense of reducing its light output by about 20%.”

  29. Mark Shapiro says:

    LED’s, the future of lighting, use direct current only, just as all electronic devices use direct current. But they all plug in to our good old reliable 120 V AC household current. Thus each LED bulb (technically a “lamp”) has its own AC to DC power supply. This adds cost, weight, and bulk to each bulb, and reduces the efficiency and the reliability.

    Wouldn’t it be great to have a standard DC voltage (with a standard plug and socket combination), so that the circuits the supply LED lights and all our electronic devices supplied DC? Choosing the optimum voltage is the key challenge. This DC standard would complement, not replace, our 120V AC standard.

    Also, PV produces DC only, and as the cost of PV panels goes down, the cost, and losses, of the inverters, becomes a higher fraction of the cost. If we want rooftop PV to become a great value, wouldn’t it be great to remove all the middlemen between the DC source and the DC uses?

    (Cue Bob Wallace for the rebuttal . . . the floor is yours.)

  30. Edward says:

    In eastern Europe, old incandescent bulbs last much longer than 70,000 hours. Some houses have their original bulbs after 50 years. They give an orangish light, but bulbs made here only last 1000 hours by intent. They will find a way to make LEDs burn out quickly too.
    Customers could change the situation, if they had enough imagination to think of the idea of things that last. Same with cars and other consumer items.

  31. Bob Wallace says:

    We’ve done this before, eh?

    A low voltage loop for lighting and electronic gadgets would be fine. IF you could get DC voltages standardized for computers, battery chargers, MP3 players, etc. Currently I’ve got at least five different DC voltages in use.

    The cost of running a DC loop would be significant for those who aren’t do-it-yourselfers. And it wouldn’t be insignificant effort for those who provide their own labor unless they were willing to live with exposed wires running around their rooms.

    But you’d still need a higher voltage loop, AC or DC. You would not be willing to pay for the very large diameter wire needed to run an electric stove/dryer/refrigerator/air-conditioner on low voltage DC.

    Running new loops, installing new outlets, replacing DC gadgets, installing one big household step-down inverter – betting this idea doesn’t get off the ground. Might happen, but someone would have to generate some significant financial savings to make it real.

    And PV, you’re still going to have to use an inverter to get it to match grid voltage/frequency. Utility companies are not going to build a second grid just to make it easier to charge your cell phone.

  32. Anne van der Bom says:


    Think. Why do these lights give off an orangish light? Because they are used at a voltage much below their design voltage. That’s why they last so long. But will that save you money? No, they will use a lot more electricity to produce the same amount of light.

    The 1000 hour lifetime is not a nefarious plot from the manufacturers to sell lamps. They actually save you money by lowering your energy consumption. Do the math and you’ll see it. The wikipedia page has the formula’s.

  33. NeilT says:

    Anne @26, @28, I find that people who switch completely to CFL think it’s excellent and provides all the light they need. I find that people who have a mix of incandescent and CFL find them poor for light and visibility.

    There’s a message there.

    I did a quick test just to verify my perception against your perception. I’m sitting in a 4.5Msq room. It has relatively light walls and a light scandinavian wood effect floor.

    I have a light fitting in the centre of the cieling which has 3 brand new 11W 550lm bulbs in it. I just looked over my shoulder at my computer bag in the opposite corner. It’s is “shadow” lit. If it had text on it (my eyesight is very good at distance), I would have difficulty reading it.

    If I had 3 60watt (can’t find them yet) bulbs in their place I would have significantly more light.

    These bulbs come to half light immediately and then come to full light after 2-3 minutes.

    It is more likely that rob’s light bulbs don’t blow because the transformers in the dimmers smooth the voltage, to whit the frequency of replacing them. Although dropping the intensity does also help. I’ve lived in places that have microspikes of thousands of volts. Doesn’t do the light bulbs much good, or dimmers…..

    BTW I’ll take note to wait 5 minutes between switching my stair lights on in France and descending the stairs (steep spiral staircase, very dark).

    I have an excellent litmus test for light bulbs. I have an ebook reader with e-ink technology. The better the light the less likely I need to wear glasses. The only time the lights are on and I don’t need to wear glasses is when the two 70w halogens are on in the lamp beside me. The 1,650 luminems coming off the CFL’s? Forget it….

  34. Mark Shapiro says:


    “We’ve done this before, eh?

    A low voltage loop for lighting and electronic gadgets would be fine.”

    And that’s primarily what I’d like to see. And the five different DC voltages you have may be THE issue. Is there one standard voltage that serves most electronics; AND how expensive and inefficient is it to step down DC voltage from a standard to each individual device? I don’t know, would like some EE’s advice. And the whole point of standardizing is that it’s not just for DIY’ers — it’s off the shelf.

    Good news: in 2009 cell phone makers agreed to standardize on micro-USB for cell phone chargers. That gets all the little stuff (and maybe even some LED lighting. LEDs are low voltage.)

    IBM has a powered-USB standard for bigger stuff, but it’s proprietary. If it became a free standard that everyone manufactured to . . .

  35. Bob Wallace I do shoot RAW and use Lightroom for first stage processing. I moved into Lightroom when Adobe bought up Pixmantec’s RawShooter which I was using. Lightroom has some good features now. But I still figure best results are achieved when the correct WB is set in camera. Sure one can alter in software but as with scanning trannies it is still best to get the correct digital image before it hits out of camera software.

    I’ll check out FastStone later.

  36. Andy says:

    Re: Neil T. “Perception may be everything, but I still have 100 watt incandescent bulbs at home. When I want to remind myself what good light was like I go home and switch them on.”

    Seriously, you need to see your eye doctor if you require 100w incandescents to read by.

    Does anyone have a good web site that rates CFL’s suitability for reading?

  37. Peter Bellin says:

    We use CFL throughout the house, and have no complaints about the light. I normally choose ‘warm’ light (?2500K).

    The older CFL’s take a few minutes to get to maximum brightness, two or three minutes is about right. Newer ones seem to brighten more quickly.

    I think rather than avoid CFL’s altogether, perhaps they will improve over time. The newer CFLs I have pruchased are superior to the older ones in terms of time to maximum brightness.

  38. Karel De Brabandere says:

    Incandescents at about 20% efficiency and LED bulbs at about 80% efficiency? I think someone mixed up luminous efficacy (in lm/W) with efficiency.

    Have a look at Compared to the ideal 5800 K black-body with 251 lm/W (100%), incandescents are typically 5-8%, while LED bulbs go up to 33%.

    However, recently, a laboratory prototype LED at Cree achieved 208 lm/W or indeed (even a bit more than) 80% of 251 lm/W…

  39. Chris Winter says:


    Here’s a test run by Popular Mechanics

    You can download a printable PDF version.

  40. Bob Wallace says:

    Lionel – As far as I know the white balance setting has no impact on RAW files (at least for all DSLRs with which I am familiar). It might have/probably does have an effect on the embedded JPEG.

    As for scanning transparencies, I don’t even want to remember those days….

  41. Jake says:

    My grandmother just had her entire apartment outfitted with CFL bulbs as part of National Grid’s program to help people out who qualify (and lower her electric bill which NGRID subsidies). She also got a new fridge out of the deal, for free, at no cost to the taxpayer because her other one was so old. It seems that when it comes to the power company’s self-interests, money is no object.

    Now it’s LED bulbs to the rescue? Good grief. No wonder there’s so little faith in the powers that be.

  42. Ronald Brak says:

    LEDs are extremely efficient. However, LED fittings for home use probably use phosphors to create a more natural light but which reduce their efficiency. Because of this it’s probably a good idea to check the efficiency information on the packet when buying them.

  43. Mark Shapiro says:

    Jake –

    Don’t worry – all those efficiency improvements help the utility, too, simply be lowering the peak demand on hot summer days.

    A new fridge and a few bulbs are a lot cheaper than a blackout — a whole lot cheaper.

  44. Mark Shapiro says:

    Karel –

    I think you’re exactly right about efficiency vs luminous efficiency.

    Incandescents are only about 5% – 10 % efficient, CFLs are about 4 times as efficient, and LEDs are about 5 times as efficient as incandescents.

    Both CFLs and LEDs have built-in power supplies, which lower efficiency a little and add costs.

  45. Mulga Mumblebrain says:

    The observation that the poor,’inefficient’ Eastern Europeans,toiling under the weight of Communist oppression, could make incandescent bulbs that lasted fifty years, tells you a lot. There is price to be paid for the legendary (in fact mythical) ‘capitalist efficiency’, and one manifestation is ‘planned obsolescence’. The capitalist builds deliberately shoddy stuff, to ensure a future market and growing demand, hence ever growing profits. Of course, they often stuff up and go broke, or find outsourcing to slave wage regimes more to their liking. Leaving that aside, the efficiencies that we could achieve by making our economy sustainable before profitable, are gigantic. The Economist gives away the quasi-religious nature of capitalist denialism.Even energy efficiency is to be denied now, along with anthropogenic climate change,the limits to growth, the inefficiency of unequal societies, the scientific method and rationality itself. It sounds like a bastardised version of ‘Jevon’s Paradox’, in regard to which they have demonstrated their flair for casuistic flexibility before.

  46. Bob Wallace.

    Perhaps I should have enlarged on my shooting which is RAW+JPEG. I often use the JPEG versions for rapid demonstration and web usage and which type will eventually be used most is not always obvious at shoot time. Whatever, I still consider it best practice to set correct colour balance at shoot.

  47. NeilT says:

    @36, Andy.

    It’s nice to know that I don’t know how to use my ebook. I’m interested to know how visiting an optician would help me distinguish the grey/black text from the grey background produced by those lights.

    After posting yesterday I was reading under the halogen lights, as usual, when I decided to move out to the main room lighting.

    It was impossible to read the display unless I held it at exactly one angle which gave the absolutle maximum light refracting at exactly the right angle to allow me to read the display. I gave it 10 minutes for my eyes to adjust but no joy. I gave up and went to bed……

    You can’t make people buy, or enjoy, something which is not the same quality as the product they were using. Especially if it costs more.

    It has nothing to do with climate change or what we need to do or anything else like that. It’s pure consumerism which is the way our society runs and we’re not going ot change that.

    So, as I say, LED, for now, is the way to go. But they have to do it properly and provide what people want/need. Today I don’t see that happening. So the products will have a slow uptake. I don’t have an issue paying for what I need, I have an issue not being able to buy it.

    I will have to console myself with the massive reduction in my energy footprint by massively insulating the house, double glazing it, removing the oil central heating and moving to wood, which in France is renewable as it comes from locally managaed forests grown for heating and replanted after each cutting. And the attendant drop in energy costs…..

  48. Robert Sullivan says:

    @Anne, and others wondering about CFL light:

    Actually, a photobiologist, Dr. John Nash Ott, did some interesting studies starting nearly fifty years ago and discovered important differences in indoor light and how the specific wavelengths of natural light impacted plants and other living things.

    One thing I haven’t seen mentioned here on this thread is the fact that CFLs contain mercury. That again seems to me to be a short-sighted solution, such as nuclear power. What do you do with the waste?

    On eastern European machinery, I note a relative’s washing machine lasted a good twenty years, or maybe it was thirty. Simple, but nearly indestructible. Their houses are similarly constructed, designed to last hundreds of years, not like the wooden houses here built for a generation or so.

  49. mike roddy says:

    Mark, #26, PE Consulting is basically commercial. Zero net energy homes can only be built cost effectively by owner/builders, and even then they’re expensive. The people at PE can provide guidance on residential, though, and send you in the right direction. One excellent book on the subject is called The Ecological Engineer, from a firm in Canada.

    Zero net and durable, inert construction is labor intensive. Our economy is set up around highly marked up products from China that a conglomerate like General Electric can profit from. The big politically connected firms won’t get involved in zero net, because resources are local, and problems can’t be solved from central factories. Designing buildings properly is an art, and our existing construction and architectural assets aren’t up to it.

    We also are still resistant to change. Hotel owners, for example, won’t even install microprocessor based room energy management systems, like the whole world uses.

  50. 1. Most complaints about CFLs in the comments are about those few available in local stores, with limited and often unlabeled characteristics. At stores like you can get CFLs in just about any size, shape, color temperature, and even base you want. Only the flood and spot bulbs can’t match or outperform incandescents (here LEDs especially shine, so to speak). Otherwise, when the right ones are selected, there is no reason to complain about the quality of CFL light.

    2. Lighting experts indicate that there are 336 lumens per Watt of white light (this is not a simple calculation because white light is a weighted mixture of wavelengths and energies). The light output of regular 100W frosted light bulbs varies between 950-1700 lumens or 9.5-17 lumens/W. Their efficiency is therefore a ludicrous 3-5%! In contrast, CFLs, T8 fluorescent tubes, and today’s best white LEDs cluster around 50-70 lumens/W or 15-21% efficiency. This difference from the 80% efficiency quoted in the article is important, as it means that there is still plenty of room for continued improvement!

    3. White LEDs are getting better quickly, are rapidly becoming available in more configurations and color temperatures, and, unlike CFLs, are nearly point sources that can be focused for less waste in many applications. However, I have found that to get what you want, you need to look closely for lumen output and color temperature, figures that are often hard to find in retail store offerings. In the meantime, online stores like can be useful sources.