The problem I had with standard bulb fittings was lumens and angle. Strip light solved that problem.
I do have Philips 100W equivilant bulbs in the lounge which are pretty spectacular, but they are warm-white.
The problem I had with standard bulb fittings was lumens and angle. Strip light solved that problem.
I do have Philips 100W equivilant bulbs in the lounge which are pretty spectacular, but they are warm-white.
I have those 100W equivalent Philips as well, best 100W incandescent equivalent I've used so far. 20W power usage, but worth every watt!
lighting in every room is key to ambience and well being
ma I suggest not just the ceiling lights.. but possibly another sort and direction of light?
example... an angle poise lamp....near or clamped too the desk over the keyboard is a very good thing for gaming and some styles of work
the bulb is secondary to the choice of lighting unit/proximity/delivery
Originally Posted by Advice Trinity by Knoxville
kalniel (12-08-2016)
Good point. In our case, it really is a box room - there's little else but a double computer desk so the ceiling light is sufficient - there's no noticeable shadowing. Illuminated keyboards helped with the old light but while they're still handy with this new bulb there's not much need.
Coming from another (warm lit) room into the study at night the 4000K still feels a little cool, but you quickly adjust. What impressed me last night though was as the light outside was dimming we just turned on the study room and kept the curtains open.. and it was like time stood still - you know those mid-summer nights where it seems to stay light for ages? It was just like that for hours - it got darker outside but seemed like summer evening light in the room still.
so ,, what you're saying is... all your neighbours could see you through the window and you were perfectly lit, like on stage,...but you were oblivious to this and you couldn't see anything out through the reflective window and felt as though you were in total privacy in your sunlit room
be cautious dear chap......
Originally Posted by Advice Trinity by Knoxville
thespian.....
Originally Posted by Advice Trinity by Knoxville
Tubelight aka Fluorescent lights ?
Dentist, and general teeth lover.
My solution, kalniel, was a set of LED bulbs that are dimmable, and have variable colour temp, by remote control. I do a fair bit of photo editing too, but find a warmer temp more comfortable most of the time. So I can set brightness according to what I'm doing, and want ambient levels at, and then cool the colour temp a bit to take the warm cast out for editing.
The remote can either be a little handheld unit or, if you buy a WiFi adapter, via an app on PC, phone etc.
The control also has four "groups", so you can put different bulbs in different groups and control on/off, brightness and colour temp for each group.
The bulbs are standard bayonet connectors, as I didn't want to change the light fitting or several angiepoise lamps, and each bulb is about the same output, when on full, as a 60w incandescent, so they're a direct replacement.
The snag? Cost, of course.
A bulb/remote pack is about £25, or bulbs are about £20 each. I got two bulb/remote packs so I have a spare remote, and several bulbs as well.
It works well, IMHO, is very convenient and I'm delighted. I can't detect any flicker from the LEDs, as I do with some CFLs.
I can't remember the supplier details but if you're interested I'll dig out the invoice and post them here.
kalniel (19-08-2016)
Variable colour temperature? Now there's a thing!
Any idea if they do it through something like RGB or do they have groups of white emitters with different phosphors?
Personally I find around 5000K a nice bright white colour, but much above that gets a bit uncomfortable. For most stuff though, I find 3000k is nice.
Thanks, yes I'd seen these were available now. Philips advertise similar. At the moment I'm really happy with the bulb I got as mentioned a few posts back, so much so that we're thinking of getting many for the rest of the house now! We'll keep warm ones for the bedrooms and lounge, but this 4K light will suit many other places.
I kinda came in at the end of the thread with limited time, but I'll read through a bit later. I do also have some "cheap" bayonet-fit standard LED bulbs, that were about £10 for five, I.e. £2 oer bulb. They are available in warm and cool, but I only have warm, as the wife doesn't like "harsh" cool bulbs. I've got thise in most of the house, certainly in heavy use areas. I haven't changed all CFLs over mainly because I'm resistant to throwing away working CFLs (obviously) and once I take them out I'm never likely to put them back in.
Should we move house, the LEDs will be going with me and, by a strange coibcidence, the older slow-start CFLs may end up being left behind.![]()
I've seen variable colour too, you know, red, gree, blue etc but to me that seems .... gimmicky.
To be honest, I've wondered how they do it, but have no idea.
I'm not aware of LEDs that can vary light output. Last time is used them, they were on or off. On dimming, which is mainly why we first bought these (for the lounge) there seems to be about 10 discrete power levels, so I assume they do that throught switching banks on/off to control overall brightness. How they do the colour temp adlustment I've no idea.
The same metjod would work, but there must be a hell of a lot of indidual LEDs to do it that way.
The bulbs themselves look similar to conventional pearl incandescent bulbs, but with a bigger "base". They're sealed and opaque, and I'm not dissecting a £20 working bulb to see how they're made.
When one fails (hopefully not for a long time) I plan on an doing a bulbtopsy. on one.![]()
Normal LED is blueish.
'Warm' LED is blueish with filter to block blue light.
Variable would presumably have one of both and you just vary the brightness ratio?
I've had a quick look online out of interest and the ones I found seem to do it by having one, or a set, of one colour temperature, say 2700k, and another of maybe 5000k, and mix the two, presumably by activating more LEDs or varying the power.
It is possible to vary LED power, either by current-limiting or PWM i.e. pulsing them on and off quickly, which is why PWM can appear as flicker if the frequency is too low.
Using normal triac dimmers is a bit more complex because LEDs themselves are non-linear WRT voltage and current, and in the case of designs fed by a switch mode power supply, chopping up the waveform with triacs will just make the SMPS unhappy and stop functioning after a point, before which the output will be constant anyway. I've not looked into it much but one way LED bulbs (as in retrofit BC/ES types) can be made dimmable is with some extra electronics to examine the waveform from the dimmer and pass the 'value' to the current limiter or PWM controller, and I assume using a big capacitor after the rectifier to smooth out the gaps in the supply voltage. It's one of those cases where it's a bit of a bodge to make them work in existing installations.
I've also just spotted a datasheet for an IC specifically designed for this purpose if anyone's interested: http://www.ti.com/lit/ds/symlink/lm3445.pdf
Edit: oops cross-post. @kalniel - all white LEDs (that I know of) consist of a blue LED with a phosphor to turn some of that blue light into other colours to make it white. Cool/warm LEDs just have different phosphors to vary the intensity of each part of the spectrum.
kalniel (19-08-2016)
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