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Lights Out for Incandescent Lightbulbs
ChadTower:
--- Quote from: crashwg on December 20, 2007, 03:28:50 pm ---While we're on the subject of why CFL sucks... Don't they wreak havoc on video recordings, both digital and analog?
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I record kids' stuff fairly often in my house and haven't noticed it yet. Maybe newer cameras are better at dealing with it but we don't seem to get the flicker issues. I wonder if that is an issue with rooms that have multiple CFLs lighting them? Our rooms are mostly all small enough that one strong one does the whole room.
patrickl:
When you have flicker you really have an old lamp. They have switched to electronich switching ages ago and that works at tens of thousands of hz. This also solves the slow startup. Odd that they still sell the crappy models with the slow startup. I recall there were actually magnetic waves coming from. There must be a site with some info about this.
:edit:
Here is more info:
Answers.com: compact fluorescent lamp
I thougt it was a starter, but of course it's the ballast that's now electronic instead of magnetic
Answers.com: electrical ballast
--- Quote ---Electronic ballasts usually change the frequency of the power from the standard mains (e.g, 60Hz in U.S.) frequency to 20,000 Hz or higher, substantially eliminating the stroboscopic effect of flicker (100 or 120 Hz, twice the line frequency) associated with fluorescent lighting (see photosensitive epilepsy).
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--- Quote ---Instant start
Starts lamps without heating the cathodes at all by using a high voltage (around 600 V). It is the most energy efficient type, but gives the least number of starts from a lamp as emissive oxides are blasted from the cold cathode surfaces each time the lamp is started. This is the best type for installations where lamps are not turned on and off very often.
Rapid start
Applies voltage and heats the cathodes simultaneously. Provides superior lamp life and more cycle life, but uses slightly more energy as the cathodes in each end of the lamp continue to consume heating power as the lamp operates.
Programmed start
More advanced version of rapid start. Applies power to the filaments first, then after a short delay to allow the cathodes to preheat, applies voltage to the lamps to strike an arc. Gives the best life and most starts from lamps. This is the preferred type of ballast for applications with very frequent power cycling such as vision examination rooms and restrooms with a motion detector switch.
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ahofle:
--- Quote from: shardian on December 20, 2007, 02:41:28 pm ---Next time you are in the light aisle, take a look inside the lens of a CFL flood light. It is a spiral inside of a reflector and lens.
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Yes of course (it's also annoyingly obvious when you first turn them on). My understanding is that the ventilation warning is only to prevent the CFL from overheating which shortens its life. What I was wondering is if the actual lamps inside the enclosed type CFLs were designed to run cooler than standard CFLs and thus require a longer warmup. :dunno
SavannahLion:
--- Quote from: shardian on December 20, 2007, 03:39:38 pm ---
--- Quote from: crashwg on December 20, 2007, 03:28:50 pm ---While we're on the subject of why CFL sucks... Don't they wreak havoc on video recordings, both digital and analog? I know they used to (at least full sized fluorescents did.) I remember some camera I used a while back that the video looked like a horror movie with how much flicker the light induced.
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Warning: tangent incoming.
I am working on a Library right now in which the architect calls for lay-in tile ceilings, but then there isn't a single drop in light fixture in the building. :dunno Everything was wire hung fluorescents hung upside down.
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Here's another tangent.
We all know fluorescents produce UV light which is converted to visible light before leaving the tube. When I worked at Home Depot, I noticed a large percentage of fluorescent tubes that lacked the white phosphor coating right at the very ends of the tube. Usually the last 1/2 inch or so. In the same breath, I've spotted some tubes that exhibit noticeable thin or bald patches in the coating (though this is rare). Chances are good you'll get a tube with bald patches. Even with 100% coverage inside the tube and despite what manufacturers tell you, fluorescents are not 100% efficient at converting UV light to visible light. Some of that light escapes. While working at a archival facility, this was precisely the problem that was encountered. To protect the long term life of the artifacts, everything was put into boxes or wrapped in paper to prevent light from reaching the artifact. Other options (though we didn't practice it) was to wrap the fluorescent in a UV barrier. However, these are relatively expensive to implement. UV is permanently damaging to artifacts. It is cumulative and there is no such thing as reversing the effects. The effects are gradual, but in twenty or thirty years, your "antique" cabs are probably going to exhibit noticeable light damage.
Standard incandescents on the other hand, usually do not emit much (if any) UV and, I believe, are the preferred method of lighting when dealing with preservation. I intend to buy a UV meter, like the kind used by xeroderma pigmentosum patients to decide best storage practices.
--- Quote from: patrickl on December 20, 2007, 04:12:31 pm ---Odd that they still sell the crappy models with the slow startup. I recall there were actually magnetic waves coming from. There must be a site with some info about this.
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In the U.S. you will always find crappy products that are still marketed. Sounds obvious, but it doesn't seem that way to a lot of people. To put it another way, Joe has a choice to buy CFL X which is cheaper but made like dog ---steaming pile of meadow muffin--- or CFL Y which is more expensive but uses the latest technology. Given this is a country where Wal*Mart makes BILLIONS despite the economic damage it does, it should be obvious what Joe is going to buy.
patrickl:
The natural daylight lamps even advertise that they emit UV. They claim they use special glass (crystal?) to allow the UV to get out to make the light as similar as possible to the light from the sun. LOL, guess that's all bogus then.
On the other hand looking at how much UV comes from a CFL, it's not a lot. Everything you wanted to know about Compact Fluorescent Bulbs, including the mercury problem
--- Quote ---Manufacturers say, however, that there is no health risk and that eight hours of exposure to CFL UV is about the same as one minute in full sunlight. But, photographs, artwork, some fabrics, and some photoreactive chemicals used in furniture finishes are susceptible to degradation from any increased levels of UV over time. So this is something to consider.
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I liked this one too ;D
--- Quote ---So CFLs won't save the planet, but they might put off its demise for a month or two.
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