Does fluorescent light have to be ugly?

[FromBelgiumWithLove]

That's dichroic film, not dichromatic.
It's a completely different thing.

They're different indeed. The film in Polaroid instant cameras* was trichromatic, otherwise it couldn't have produced proper colour images. However, the original Polaroid filter that made Mr. Land's fortune is dichroic, in regards to the polarization of light, not its colour.

* Polaroid have stopped making that film, but a brave little Dutch company bought an old Polaroid factory, and are still making it. They go by the wonderful name of The Impossible Project, and thus sell Impossible film, and Impossible cameras.

 

[McHrozni]

The first time I put a fluorescent bulb into a lamp I was appalled. It seemed to give everything a sickly gray glow. I waited to see if I would get used to it, but no. I also accidentally broke one and wasn't sure of cleanup protocols.

Then I noticed a halogen option appear and I find these much nicer than fluorescent.

What other options are out there and how do they square up environmentally? Also, what happens if you put a 3-way bulb into a lamp without a 3-way switch?

Fluorescent bulbs are on the way out. Opt for LEDs instead. You can get them in brain-friendly spectra now, and almost offer all the benefits of a halogen, need even less power than fluorescent, don't break easily/at all, get to full power instantly ... etc.

McHrozni

 

[MRC_Hans]

I think the differences between the three types of lamps are well illustrated by the three attached puctures. You can make your own with a CD spectrometer (google it for how to construct one, it is very simple).

As you can see, the incadescent has the best spectrum. LED is fair, and flourescent is really hopeless.

Hans

 

[McHrozni]

I think the differences between the three types of lamps are well illustrated by the three attached puctures. You can make your own with a CD spectrometer (google it for how to construct one, it is very simple).

As you can see, the incadescent has the best spectrum. LED is fair, and flourescent is really hopeless.

Hans

Looks nice

Is halogen similar to incandescent?

McHrozni

 

[elgarak]

Looks nice

Is halogen similar to incandescent?

McHrozni

Halogen IS incandescent, it's just that the filament is hotter than normal incans, and thereby whiter/bluer.

Halogen/incan spectrum is essentially black-body radiation, and for practical purposes similar to sunlight. The spectrum changes and shifts in a defined manner depending on the temperature of the emitter, hence you only need this temperature to know exactly how the spectrum looks, and which color rendition it has (hence "color temperature").

Fluorescent bulbs and LEDs have different spectra. CFLs start with UV light, which is then converted to whitish with the phosphor. LEDs start with blue, again converted with a phosphor, and there's always a strong blue peak in the spectrum of LEDs. The thing is, one can adjust this spectrum a LOT more than the incandescent black-body spectrum, and get a whole lot more tint variation. Exactly how the spectrum can be adjusted took a few years experimentation (hence early CFLs or LEDs having very unusual spectra and tints), and is still an ongoing process, in particular with LEDs. The spectra of CFLs or LEDs cannot simply be described by one single parameter like color temperature, but since the industry tries to emulate sunlight to a great degree, most sold bulbs are as similar to black-body radiation as possible, and labeled with the incan color temperature descriptions.

The label you have to look for is "warm-white" if you want to avoid bluish tints. The bluish is, however, better for certain physical work places, I found, and usually perceived brighter.

Some more of my observation:

1) LEDs are unsuited for medical examination of skin problems, even when warm white. If you need a light for that, get a halogen flashlight.

2) I have replaced CFLs in our laundry drying room with warm-white LEDs. Brightness and color tint appear to look similar at first, but I noticed that white laundry doesn't appear the clean bluish white glow it had before. Looks a bit yellowish. If you want to show off your tidy whities really tidy white, get blue/cold-white CFLs or really bright halogens .

And, frankly, the only lights I would go out and shop for general lighting purposes are LEDs. They're still somewhat expensive, but right now at a price point that you'll get the investment back with the lower power consumption and longer lifetime in a few years. And I expect the price to come down more, and the more people buy them the faster this happens. Normal incans are hard to get by now, in particular for high brightness, too breakable, and frankly, I really like how LEDs do not get hot like incans (which is a waste, and a general problem for safety and how it affects the surrounding of the lamp for me). CFLs are also too breakable, and have the nasty free Mercury when breaking and disposing.

 

[McHrozni]

Halogen IS incandescent, it's just that the filament is hotter than normal incans, and thereby whiter/bluer.

I know, which is why I would expect the spectrum to be slightly different

1) LEDs are unsuited for medical examination of skin problems, even when warm white. If you need a light for that, get a halogen flashlight.

2) I have replaced CFLs in our laundry drying room with warm-white LEDs. Brightness and color tint appear to look similar at first, but I noticed that white laundry doesn't appear the clean bluish white glow it had before. Looks a bit yellowish. If you want to show off your tidy whities really tidy white, get blue/cold-white CFLs or really bright halogens .

I don't particularly need neither I'm fine with LEDs then?

McHrozni

 

[MRC_Hans]

Looks nice

Is halogen similar to incandescent?

McHrozni

It is a type of incadescent. It will be even stronger in the blue, but otherwise the same.

Hans

 

[MRC_Hans]

I know, which is why I would expect the spectrum to be slightly different



I don't particularly need neither I'm fine with LEDs then?

McHrozni

Personally, I have changed nearly all my light sources to LEDs. Only missing are four halogens in the kitchen, which currently remain mainly for technical reasons, and two CFLs in the bathroom. I would like to get rid of the latter, but the armatures do not accomodate any current type of LED, and since I rent my home I'm reluctant to buy new armatures (but I may end up doing it).

LEDs are still rather expensive, but they pay themselves back in the typical life-span of the incadescent they replace (and then supposedly keep working for 5-10 times that period).

With the promised life-spans of LED bulbs, in the future you will be buying lamps for your bulbs, instead of the other way around.

Or, as in the case of some of the lamps I have, they go together: You cannot change the leds. *)

Hans

*) Being an electronic engineer and proficient with a soldering iron, I might do just that, nevertheless.

 

[jaydeehess]

It is a type of incadescent. It will be even stronger in the blue, but otherwise the same.

Hans

Perhaps mention should be made that what we commonly refer to as incandescent bulbs, have tungsten filaments within a near vacuum, while halogen incandescent bulbs fill the space with an inert gas( well, one that won't interact with the filament) from the halogen family in the periodic table. This results in enabling the filament to get hotter.

Older TV studio lamps were halogen and the studio could get quite unbearably hot. Newer fluorescent and LED lamps alleviate that while lowering power costs.

 

[Madalch]

Perhaps mention should be made that what we commonly refer to as incandescent bulbs, have tungsten filaments within a near vacuum, while halogen incandescent bulbs fill the space with an inert gas( well, one that won't interact with the filament) from the halogen family in the periodic table. This results in enabling the filament to get hotter.

An inert gas in the halogen family? No such thing.

The way I remember the explanation, the temperature of the tungsten filament is limited by the slow evaporation of tungsten in a vacuum (which condenses on the inside of the bulb and reduced the mass of the filament). A small amount of iodine in the bulb will react with the tungsten on the inside of the bulb to give volatile tungsten iodide, which converts to a gas when the bulb is on, but if it touches the filament, decomposes to put the tungsten back where it belongs.

 

[Beanbag]

An inert gas in the halogen family? No such thing.

The way I remember the explanation, the temperature of the tungsten filament is limited by the slow evaporation of tungsten in a vacuum (which condenses on the inside of the bulb and reduced the mass of the filament). A small amount of iodine in the bulb will react with the tungsten on the inside of the bulb to give volatile tungsten iodide, which converts to a gas when the bulb is on, but if it touches the filament, decomposes to put the tungsten back where it belongs.

Sort of a Chinese fire drill for tungsten.

Beanbag

 

[Brian-M]

Perhaps mention should be made that what we commonly refer to as incandescent bulbs, have tungsten filaments within a near vacuum, while halogen incandescent bulbs fill the space with an inert gas

You're getting your incandescents mixed up.

19th century globes with carbonized cotton filiments were in near-vacuum (and needed very thick glass to prevent them from imploding).

20th century globes with ductile tungsten filaments were filled with inert gas. They were also more than twice as energy-efficient than 19th century globes, and filing them with gasses instead of vacuum meant they coluld use thinner glass, making them cheaper to manufacture.

Halogen globes contain halogens instead of inert gasses, which makes the filament last longer. This also means they can also make them run at a higher temperature without burning out very quickly as a regular incandescent would, so that's what they do, because the hotter temperature produces a whiter light and produces more visible light for the same amount of energy, making them more efficient than regular tungsten incandescents.

 

[Bob001]

....
1) LEDs are unsuited for medical examination of skin problems, even when warm white. If you need a light for that, get a halogen flashlight.
.....

Why would that be, if the color temperature and brightness are the same? Is there some other quality that makes LED light different from florescent and halogen?

 

[McHrozni]

Personally, I have changed nearly all my light sources to LEDs. Only missing are four halogens in the kitchen, which currently remain mainly for technical reasons, and two CFLs in the bathroom. I would like to get rid of the latter, but the armatures do not accomodate any current type of LED, and since I rent my home I'm reluctant to buy new armatures (but I may end up doing it).

LEDs are still rather expensive, but they pay themselves back in the typical life-span of the incadescent they replace (and then supposedly keep working for 5-10 times that period).

Having recently renovated, I didn't find LEDs to be expensive at all. A regular light without a bulb was about the same as a LED light. I actually got rather nice LED lights with bulbs and a replaceable transformer for less than what I'd pay for a comparably nice regular light, without bulbs.

Regular LED bulbs with built-in transformer were about the same as high-end fluorescent ones, with rapid 100% lighting.

I guess it depends a bit on where you live as well I eventually opted for one fluorescent in the bathroom because watertight light would only accept fluorescent, another halogen in the bathroom above the mirror, and the rest are LEDs. Kitchen LEDs rule, by the way.

McHrozni

 

[elgarak]

An inert gas in the halogen family? No such thing.

The way I remember the explanation, the temperature of the tungsten filament is limited by the slow evaporation of tungsten in a vacuum (which condenses on the inside of the bulb and reduced the mass of the filament). A small amount of iodine in the bulb will react with the tungsten on the inside of the bulb to give volatile tungsten iodide, which converts to a gas when the bulb is on, but if it touches the filament, decomposes to put the tungsten back where it belongs.

The way it works is thus: At the hot filament, tungsten evaporates (simply because it's hot). The tungsten gas floats around in the bulb, and eventually settles down on the glass (which is cooler than the filament). In a normal incandescent, that's the end of it. The tungsten on the glass develops a dark film, the filament looses so much tungsten that it breaks, and the bulb is dead. In a halogen bulb, the halogen reacts with the tungsten near or on the glass (the relatively cool region of the bulb. It's possible that it's only a surface reaction, only happening when the tungsten has settled down on the glass surface, and not within the free gas), forming a tungsten-halide. This molecule floats around, and it breaks up at higher temperatures, that is, at the filament. The halogen thus transports the tungsten back to the filament.

It also means that halogen bulbs should not be dimmed very much. Dimming reduces the temperature of the filament, and the breakup of the tungsten-halide cannot happen.

 

[ceptimus]

The reason that halogen bulbs don't last forever is that although the tungsten gets deposited back on the filament, it doesn't know where on the filament it should be deposited.

So over time the filament gets thicker in some places and thinner in others until, finally, it burns through at the thinnest place.

 

[jaydeehess]

An inert gas in the halogen family? No such thing.

Actually I said

well, one that won't interact with the filament

In that I see I was still incorrect. That's what I get for believing the explanation I got from a salesman(studio lighting)

 

[Ziggurat]

Why would that be, if the color temperature and brightness are the same? Is there some other quality that makes LED light different from florescent and halogen?

Neither fluorescent lights or LED lights are good for something like medical examination of skin conditions. They're also not great for making art or doing makeup or any other purpose where color accuracy is important. That's because neither LED's nor fluorescent lights have smooth spectra. If an object you're looking at is strongly reflective in a region where there's a sharp dip in the emitted light spectra, that component of its color will be suppressed. So that object will look very different from what it would look like in sunlight, even though other objects may look exactly the same.

Halogen and other incandescent lights have pretty smooth spectra, and in that respect, they more closely resemble sunlight. Even if the color temperature is different from sunlight, you won't get those gaps in the spectra, and so while the apparent color of everything may shift a little (everything will look a little less blue/green and a little more red/yellow with a 2700K bulb), you won't get certain objects looking wrong relative to everything else.

 

[MRC_Hans]

Neither fluorescent lights or LED lights are good for something like medical examination of skin conditions. They're also not great for making art or doing makeup or any other purpose where color accuracy is important. That's because neither LED's nor fluorescent lights have smooth spectra. If an object you're looking at is strongly reflective in a region where there's a sharp dip in the emitted light spectra, that component of its color will be suppressed. So that object will look very different from what it would look like in sunlight, even though other objects may look exactly the same.

Halogen and other incandescent lights have pretty smooth spectra, and in that respect, they more closely resemble sunlight. Even if the color temperature is different from sunlight, you won't get those gaps in the spectra, and so while the apparent color of everything may shift a little (everything will look a little less blue/green and a little more red/yellow with a 2700K bulb), you won't get certain objects looking wrong relative to everything else.

Correct, but again: LED is far smoother than flourescent (re. the spectra I posted earlier). LEDs have two few rather narrow dips in the blue region, while flourescent have wide black bands all over the spectrum.

For the the dedicated, however, there should be incadescents (e.g. halogens) in your kitchen, by your make-up mirror, and in your art study. Also as needed for medical examination, but I assume specialists are aware of their particular needs.

Hans