Am 30.07.2014 20:03, schrieb Patrick Elliott:
> On 7/30/2014 1:13 AM, scott wrote:
>>> Trouble is, those mini fluorescent things take about quarter of an hour
>>> to turn on...
>>
>> They must be *very* old ones then. Even the 99p ones that Tesco were
>> selling a while back turn on instantly. Given the price of them, and
>> even the price of LED lights now, it's pretty much a no-brainer to just
>> throw all your incandescent bulbs in the bin immediately.
>
> Yes well.. Here in the good old US, you get morons like the one who
> tried to tell me that, "other lights hurt my eyes", which I supposed
> meant that the dimwit was still trying to use the really old ones, which
> flicker, and thought that the new ones did too. He also whined about
> them not being "natural light", which is, you know, the whole point of
> the bulbs with a blue coloration to them, to make them more natural, as
> per outdoor light. So the clown was actually complaining that he didn't
> like light that actually bloody **was** a more natural color, instead of
> the ugly yellowish stuff standard incandescents produce. lol

For private homes it's probably healthier -- in terms of day/night 
rhythm and anything related to that -- to use the more yellowish stuff.

On the other hand, for work places where good old daylight isn't 
sufficiently available for one reason or another, bright blueish 
illumination is kind of a must. But they've mostly been using 
fluorescent lamps for ages anyway.

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> flicker, and thought that the new ones did too. He also whined about
> them not being "natural light", which is, you know, the whole point of
> the bulbs with a blue coloration to them, to make them more natural, as
> per outdoor light.

Saying that, we ordered "daylight" colour LED bulbs, and seriously 
several times I've come downstairs in the evening and thought "ooh the 
sun's still out", only it was just the lights on. When you are used to 
that, the other bulbs looks horribly yellow and dirty/old fashioned. I 
guess with almost everything, it's just what you're used to, and people 
generally resist change.

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> Well, you could.. But you would have to a) add a heat sink,

There are light fittings specially designed for LEDs now, where the 
light fitting itself is the heat-sink. This seems like a good idea.

> b) use
> higher end LED which are way brighter than the ones usually found in
> those things,

Higher brightness = more heat. You can get ones that are marginally more 
efficient, but you're still generating roughly the same amount of heat, 


> and c) throw out the transformer setup on them, and go
> with a straight DC power connection, with the right voltage range.

Actually that is quite common here, if you've got multiple low-voltage 
lights then you have one transformer "brick" (that attaches above the 
ceiling somewhere) with DC running to each bulb. It's especially common 
in bathrooms as it means you can run standard lights (rather than 
expensive IP rated ones) much closer to a shower/bath than the 
regulations would allow with mains power.

> Since, short of wiring your house yourself to provide 5v and 12v lines,

I don't think it will work very well trying to wire an entire house with 
5V (or even 12V lines). The total current will be large, which means 
thicker cables required, and over longer runs you'll get significant 
voltage drop due to the cable resistance. Dropping a few volts when you 
switch on a 13A kettle at 220V is no issue, but dropping from 5V to 2V 
when you switch on a room full of LEDs is obviously an issue. There's 
room for some innovation here I think.

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> On 30/07/2014 09:13 AM, scott wrote:
>>> Trouble is, those mini fluorescent things take about quarter of an hour
>>> to turn on...
>>
>> They must be *very* old ones then. Even the 99p ones that Tesco were
>> selling a while back turn on instantly. Given the price of them, and
>> even the price of LED lights now, it's pretty much a no-brainer to just
>> throw all your incandescent bulbs in the bin immediately.
>
> I have yet to see a fluorescent bulb that works instantly. Oh, they all
> strike instantly, but it takes about quarter of an hour for them to
> "warm up" to the point where they produce any appreciable quantity of
> light.

For sufficiently small values of "an hour".  Unless it's -5C in your 
living room, CFLs should warm up within a minute or so.

> And even then, they always seem a bit dark.

YMMV.  I have 2 100W-equivalent in my basement, and I can barely look at 
them without seeing spots after I turn my eyes.

> LEDs sound like a nice idea, but the light they produce is usually very
> directional, and they're not really bright enough. You'd need to coat
> your whole ceiling with them.

I don't get this.  Here, we have warnings that LEDs are too bright and 
can actually injure your eyes if you look directly at them.

>
> As a matter of fact, my new flat has LED downlighters in the ceiling of
> the kitchen. Consequently, no matter where you stand, you are ALWAYS
> casting a shadow over the work surface.

Just turn on radiosity, that will solve the problem.
;)

> A normal light, suspended just
> below the ceiling and throwing light in all directions, doesn't seem to
> suffer this problem nearly as much.


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/*   gmail.com     */}camera{orthographic location<6,1.25,-6>look_at a }

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> I have yet to see a fluorescent bulb that works instantly. Oh, they all
> strike instantly, but it takes about quarter of an hour for them to
> "warm up" to the point where they produce any appreciable quantity of
> light. And even then, they always seem a bit dark.

You do realise that CCFLs come with different power ratings and 
different light outputs, exactly like incandescents? If "they always 
seem a bit dark" then maybe you are always buying ones with too low 
power for the room?

> LEDs sound like a nice idea, but the light they produce is usually very
> directional,

Most "candle" type LED bulbs will actually consist of multiple LEDs 
pointing in all different directions with scattering/diffusing lenses. 
If you buy LED spotlights/downlighters then yes you will get a 
directional light pattern, that is the whole point (same if you buy a 
halogen downlighter).

> and they're not really bright enough. You'd need to coat
> your whole ceiling with them.

Realistically you're going to get equivalent of maybe 40-60W 
incandescent from a single "normal" LED bulb. If you are used to using a 
single 100W bulb to light a room then you won't be able to replace it 
with a single LED bulb, but if (like me) you had those light fittings 
that take 3x or 5x 40W halogen/incandescents then you can easily make it 
brighter than it was before with LEDs.

> As a matter of fact, my new flat has LED downlighters in the ceiling of
> the kitchen. Consequently, no matter where you stand, you are ALWAYS
> casting a shadow over the work surface. A normal light, suspended just
> below the ceiling and throwing light in all directions, doesn't seem to
> suffer this problem nearly as much.

That's because they are downlighter spots, nothing to do with the fact 
that they are LED. You'd have the same issue with halogen spots. 
Kitchens often used to have full-sized fluorescent tubes, which actually 
worked quite well, they just went out of fashion. A "normal" uplighter 
works by throwing the light onto the ceiling and it reflecting back 
down, LED uplighters will do exactly the same, but typically you don't 
have them in kitchens.

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Am 31.07.2014 15:16, schrieb Francois Labreque:

>> LEDs sound like a nice idea, but the light they produce is usually very
>> directional, and they're not really bright enough. You'd need to coat
>> your whole ceiling with them.
>
> I don't get this.  Here, we have warnings that LEDs are too bright and
> can actually injure your eyes if you look directly at them.

That's probably because the light comes from a very small spot, so you 
can easily focus all of the light energy on a very small region of your 
retina.

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Am 31.07.2014 15:44, schrieb scott:

>> As a matter of fact, my new flat has LED downlighters in the ceiling of
>> the kitchen. Consequently, no matter where you stand, you are ALWAYS
>> casting a shadow over the work surface. A normal light, suspended just
>> below the ceiling and throwing light in all directions, doesn't seem to
>> suffer this problem nearly as much.
>
> That's because they are downlighter spots, nothing to do with the fact
> that they are LED. You'd have the same issue with halogen spots.
> Kitchens often used to have full-sized fluorescent tubes, which actually
> worked quite well, they just went out of fashion.

I don't know about the UK, but in Germany such kitchen lights would 
often not be fluorescent tubes at all, but so-called "Linienlampen" - 
incandescent light bulbs in a tubular shape with a long filament and 
special sockets.

http://de.wikipedia.org/wiki/Linienlampe#mediaviewer/Datei:Linestra_with_visible_filament.jpg

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> I don't know about the UK, but in Germany such kitchen lights would
> often not be fluorescent tubes at all, but so-called "Linienlampen" -
> incandescent light bulbs in a tubular shape with a long filament and
> special sockets.
>
>
http://de.wikipedia.org/wiki/Linienlampe#mediaviewer/Datei:Linestra_with_visible_filament.jpg

Ooh interesting, never seen or heard of that before. I don't think they 
were very common, if available at all here. All the ones I remember 
always had the starter ballast in the side, which presumably is not 
needed for the Linienlampen.

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>> As a matter of fact, my new flat has LED downlighters in the ceiling of
>> the kitchen. Consequently, no matter where you stand, you are ALWAYS
>> casting a shadow over the work surface.
>
> Just turn on radiosity, that will solve the problem.
> ;)

Win.

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On 28/07/2014 05:20 PM, scott wrote:
> And are you planning to make the animation public?

https://www.youtube.com/watch?v=8s7I80H96CM

Worth it, eh?

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