Why is it that when one wants cfls, one is forced to have the weird light output that many find hazy and hard to see in? I'd have thought that the really white phosphoreds would add very little to the cost and be much better for lighting purposes, or is the cream/green/yellow fuzzy one very much more efficient or something? It even makes my eyes feel tired even though I cannot see in it.
Brian
I really don't know what it is about CFLs over linear flourescents. I have absolutely no problem whatsoever seeing under incandescents or linears of any colour persuasion, neither do I find their light objectionable in any way. However, I hate the sickly light that CFLs generate, and have great trouble reading under them. None of them of any colour temperature or CRI seem to suit me. About the only thing that I can say is that they use a tricolour phosphor mix, and this produces a highly discontinuous spectrum compared to daylight or incandescent light, but then the spectrum from linear flourescents isn't very clever, either.
Lots of people will now jump on the thread and say that they can't see anything at all wrong with CFLs, and that the light from them is perfect etc etc. Maybe this is true for them, and I'm sure most people, but it is not for me, and apparently Brian. I do have a degree of colour blindness, and maybe it's this, combined with the 'holey' spectrum, that combines to make their light objectionable to me.
On a more practical level, I tried putting one in my bench light a while back. Unfortunately, it was worse than useless for what I do (electronic service work), as the discontinuous spectrum played havoc with being able to correctly identify resistor colour code bands. Orange was barely distinguishable from brown and sometimes red, and blue, green and grey were also a problem with some resistor types. I have no such problems working under incandescent light.
Arfa
Yes. These days I cannot see enough to worry about light for seeing but when they first came out it was obvious that they were very odd. Now most people I know look around for those rare very white ones so it can be done, and really as the colour of the light is rather important as you have said, it seems totally daft to go on using such a bad example. Many might suggest its a ploy to get people to buy add in light like desk lamps as these do seem to use whiter lights. Brian
As an aside. If these are thre colour, and the idea is to make white from red blue and green, and tvs use red blue and green to make white, then the actual colour of the colours of rg and b used must be way off on the lamps. When we used to make TVs in this fair land from scratch, we had a standard white light made from yes a fl tube with calibrated colour. That was back in the 70s so I just do not get it, all I can think is that the perceived efficiency is greater using this stuff.
Brian
What do they use in Asda etc? I don't last long in these places before my eyes start to smart.
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I think Asda use dimming high frequency ballasts with linier tubes, and they do dim them when the night shift is working when the store is closed.
They may even dim automatically depending on the amount of natural light they get through the skylights, you would be hard pressed to notice this if they do.
They also use LED lights strung low over fruit & veg.
Could not agree more.
We have spent considerable effort in sourcing ones which are acceptable to us. They are much whiter than standard "tungsten filament replacement" ones but are not that horrible blue-ish colour of many higher colour temperature lamps.
Top posted for Brian`s ease of reading
Think phosphor blending is a dark art, tri phosphor tubes are pretty much a standard over old halo phosphors nowadays but its the choice and realative mix of the phosphors that makes a difference.
With a CRT can vary the level of excitation given to the phosphor.
In a fluro tube you coat the tube , dose it with its fill and seal it up, its getting the blend of phosphors right with the right gas mix and pressure to get a decent quality of light.
At other end of quality manufacture its possible to get light out with just about any old mix , it might have a horrible green cast , but it produces light.
Nichia the company that developed the first white and blue LED`s are a phosphor blending company going back to the 1950`s, until supporting Shuji Nakamura to develop blue and white LEDs in the mid nineties. Nichia still make the nicest white LEDs.
Some specialist fluros appear white but have a boost in one colour or other, like the ones with a red boost intended for fresh meat counters.
Still prefer halogen for living areas myself.
Cheers Adam
Taa. I could not work in a place with lights like that.
What's the make/model and source, please? I'd be interested in those.
Hmmm. They are described as being Photo lamps -
4 DAYLIGHT BULBS 5000k, Trumpet Top,Photo,Craft=E2=80=8Bs,20w BCobtained from:
Lamp manufacturers spent some time trying to work out what the light properties are that make people dislike CFLs versus filament lamps.
The bottom line is they can't find any - in double blind trials, for those who claim to dislike CFLs, their like or dislike of lamps depends on if they think the lamps are CFLs or filament, and not if the lamps are actually CFL or filament lamps.
Sounds like the sort of study pharmaceutical companies try on us. I hate the damned things.
Ouch - almost as much as good LEDs!
Thanks for the link. I like the 'trumpet' shape as it exposes a bit more of the tube so the output should be more than a straight spiral.
I should have read that properly! Not as dear as I misthought - I've ordered
I have to say, me too. There's a hotel that I stay in fairly regularly in America. They changed all the reading lamps over the beds a few years ago, and without the knowledge of this, I knew immediately what they had done, the first time I switched one on. You can't see the actual lamp, as it is behind a frosted panel, but once you realise that something is different, and have a good look, you can see that the light is coming from a spiral CFL now. I also find that if you are out walking at night, you can spot the lounges (that have their curtains open) which are being lit by CFLs, immediately. The light, to me at least, has a slightly 'sick' caste to it.
We have a pair of them in our bedside lights. Fortunately, I don't read at night in bed at home, so it's of little consequence. However, when the things are on, the light they give out is sort of 'thick' and 'creamy' rather than 'sharp' and 'sparkly' (sorry, I can't come up with anything better-descriptive !) like an incandescent. The bulbs I am currently using in the main lighting areas of my house, are the ones where a pearl envelope encloses a halogen capsule bulb. Even they are now getting hard to obtain in a pearl version. I have been told by a friend who owns an electrical shop, that there is now a company that does a bayonet or ES adaptor base to accommodate halogen capsules, and a range of assorted shaped (conventional, golf ball, candle etc) detachable pearl envelopes that screw onto the base over the capsule. He says that you can't tell them, shape and size-wise, from the original all-in-one incandescents that we all knew and loved ...
Arfa
I've just ordered 4. Would prefer lower wattage too. SWMBO won't accept 6500K ones apart from the one in the futility room. The usual 2700K slow start ones are abominable, like crap lady's makeup in colour. Whatever happened to 3500K which would be more acceptable.
They aren't acceptable to most people, which is why they will be hard to find. The lux level required to make 3500K look acceptable (lookup Kruithof Curve) would be hard to achieve with CFLs - you need several linear fluorescent tubes, which is why you'll find 3500K in fluorescent tubes, but not CFLs.
The 5000K and up lamps and really just gimicks - you are effectively using a blue coloured lamp, because you will never get the lux level high enough for 5000+K to look natural. You would have to line most of the ceiling with fluorescent tubes.
A very brief foray[1] with 6500K showed, among other aspects, that the light didn't appear to be on (apart from the bleedin' obvious) but that the room was just light - it was rather peculiar. I've fitted 2*14W T5 3000K tubes in the kitchen and they're marginally less 'warm' than the 18W, 2700K that was there.
[1] It was a Prolite: buzzed, stank and wasn't up to its nominal wattage and wasn't as bright as an ordinary CFL of the same wattage.
It?s probably just that they controlled for light level. Because of the over-selling of light output of CFLs, in most places the light is just much dimmer than incandescents (and as was mentioned further up the thread, a mismatch between colour temperature and level looks odd). When I put a CFL in the loo here (a very small room) I didn?t have one that claimed to be comparable to a 40W bulb, so stuck a ?100W equivalent? one in. The light looks fine, unlike elsewhere.
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