Black Hole
May contain traces of nut
Maybe I'm not very sensitive to it, but they seemed OK to me - and still do.
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Black Hole
May contain traces of nut
Update: Yes, they definitely look warm rather than cool, and the product data says 2700K and places them towards the warm end:
Presuming they don't go pop prematurely (25,000 hours specified), I am using 21W where there used to be 120W and should never have to replace them again - that's a result. Lose a bit on the room heating though. (I only did anything about this because a while ago I was down to one bulb as the incandescents all came to the end of their service lives together, then when the last one died I fitted a LED bulb I happened to have knocking around, and then I spotted these in Aldi.)
I have inherited a heat lamp in the bathroom, which provides heat as well as light (big reflector bulb thing). As far as I know that bulb has been running (on and off!) for over 25 years!
Presuming they don't go pop prematurely (25,000 hours specified), I am using 21W where there used to be 120W and should never have to replace them again - that's a result. Lose a bit on the room heating though. (I only did anything about this because a while ago I was down to one bulb as the incandescents all came to the end of their service lives together, then when the last one died I fitted a LED bulb I happened to have knocking around, and then I spotted these in Aldi.)
I have inherited a heat lamp in the bathroom, which provides heat as well as light (big reflector bulb thing). As far as I know that bulb has been running (on and off!) for over 25 years!
OP
Deleted member 473
2700k is warm. It's a long time since we used incandescent bulbs but cfls put out a load more lumens than less. With a superior cri too, hence my cave dweller remark.
None of our Auraglows have blown yet, nor two latest generation Philips leds. I am feeling more optimistic about leds now apart from the awful cri.
None of our Auraglows have blown yet, nor two latest generation Philips leds. I am feeling more optimistic about leds now apart from the awful cri.
Black Hole
May contain traces of nut
What? You frequently accuse me of being of low luminosity, but do you think that may be more because of your inability to put a meaningful sentence together?
OP
Deleted member 473
Watt for watt, leds are far dimmer than cfls.
Black holes are, on the other hand,...
Black holes are, on the other hand,...
Ezra Pound
Well-Known Member
Do you have any figures to back that statement up?
Black Hole
May contain traces of nut
Spot the difference: 7W LED, 12W CFL, 60W GLS. Which is which?
Shadow test, the shadow of the left-most lamp above is furthest from the camera:
Shadow test, the shadow of the left-most lamp above is furthest from the camera:
Black Hole
May contain traces of nut
You're right, and the lack of light in the upper half of the globe for the LED bulb is a give-away, but I submit that there ain't a lot of difference. I found a 40W GLS was noticeably dimmer.
I'll see if I can find a 7W CFL in my collection...
I'll see if I can find a 7W CFL in my collection...
OP
Deleted member 473
The one on the right looks really dull. As cfls and leds emit roughly the same lumens per watt, but the led bulb is lower wattage, I assume the right one is led. I would equate 12w cfl with 60w incandescent.
The poor cri of the led is going to make it feel dull under it anyway.
As a scientific point, you can't compare them this way. There is no indication of how directional the light emission is. You are comparing candelas in the direction of the camera.
The poor cri of the led is going to make it feel dull under it anyway.
As a scientific point, you can't compare them this way. There is no indication of how directional the light emission is. You are comparing candelas in the direction of the camera.
Black Hole
May contain traces of nut
That's just plain ridiculous and based on no experience. The upper half of the globe on the right is dim, certainly, but the rest is practically indistinguishable from the others (and brighter than the CFL). The shadow test shows you how similar the light outputs are directly under the lamps. I can assure you that with the whole fitting populated the light in the room is as bright as anyone would want - and there is no turn-on delay.
Trev
The Dumb One
Oh FFS leave it out. BH was not doing a scientific experiment. His experiment is a subjective real life observance experiment and as such does show what he intended it to do.
What's more to the point, what's the payback time of replacing CFL with LED lamps?
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Ezra Pound
Well-Known Member
Black Hole
May contain traces of nut
Not much point, unless you find the start-up time for CFLs particularly annoying or want to work them on a dimmer. I have found the CFLs fail at a similar rate to GLS - they don't seem to meet their promises on service life (I have no recorded evidence).
As it happens I was replacing GLS because they had reached EoSL, and happened upon these dimmable LEDs as an Aldi special so bought some "for the team". I still have concerns about longevity due to overheating, and I also suspect that the brightness will go down with age.
It has also long been my intention to run this particular light fitting on a dimmer, and while dimming GLS is wasteful of energy (the emitted spectrum shifts to the IR, and and the instantaneous current increases because the filament temperature goes down), dimming LED lamps should have a more proportional response in terms of energy consumed.
Black Hole
May contain traces of nut
It wasn't all that unscientific - I would love to know how Mike0001 justifies his comment that "you can't compare them this way". I can, and I have. The direct photo of the globes isn't an accurate measurement, you would have to account for their distances from the camera, but the camera imaging system nonetheless has a known response to light intensity and spectrum. The shadow photo provides a direct measure of the relative brightness and colours of the lamps in the more-or-less forward direction.
Maybe I "can't" compare them that way because the result doesn't support his negativity towards LED lamps?
Black Hole
May contain traces of nut
Left to right: 7W LED, 40W GLS*, 8W CFL. Note that, as per the previous post, the camera exposure was set to resolve the luminosity of the globes not the illumination in the room.
For the uninitiated: GLS = General Lighting Service, ie normal tungsten-filament incandescent lighting where the light is produced by a hot glowing wire together with a great deal of energy wasted as heat; LED = Light Emitting Diode, light produced by an electronics device with relatively little energy wasted in the form of heat; CFL = Compact Fluorescent Lamp, light produced by a miniaturised fluorescent tube like the traditional "strip light", again with relatively little waste heat but with a short period before the lamp reaches full brightness. Fluorescent tubes create light by using a phosphor powder coating inside the tube to convert the UV from the electrical arc inside into visible light.
Clockwise from 1 o/c: shadow of the 7W LED; 8W CFL, 40W GLS.
The point of the shadow photos is that they provide a means to compare the illumination from multiple light sources, and even measure the relative intensity of two light sources with a ruler being the only calibrated standard necessary. If one wanted to measure the relative brightnesses of two sources, one would move one of the sources closer or further away from the screen until the two shadows were the same darkness, and then the relative intensities of the sources can be determined from their relative distances and the inverse square law. Comparing the shadows to achieve the same darknesses can be tricky if the sources have different spectra (ie colours).
In these cases, the shadowgraphs are only used for comparison. In the above, the LED source clearly creates the darker shadow and therefore is by far the strongest source in the forward direction. The CFL comes second, with the GLS a close third.
The overall light output of each lamp is spread around the room however, and not just in the forward direction. GLS and CFL have a more-or-less full spherical distribution, with just the large base of the CFL creating a shadow in the reverse direction. LEDs mostly emit in the forward direction (a hemisphere, with a drop-off towards the edges), but these particular lamps have (maybe) multiple emitters arranged pointing in different directions behind a diffuser so that the output is uniform in all directions (except behind, where typically light is not needed anyway). Because of these differences in distribution, it is difficult to compare the total light output from these sources (although it would be possible, either by measuring over the whole sphere and integrating, or by arranging reflectors to make all the light output from any source go in the forward direction).
With all that in mind however, in my opinion the total output of the 7W LED lamp still exceeds the total output of the 8W CFL by a small margin, and the total output of the 40W GLS by a significant margin.
As far as colour rendering goes, maybe somebody has a spectrometer they can lend me. Perhaps there are standard colour charts - paint manufacturers' colour swatches might do. The sort of chart opticians use to diagnose colour blindness might work too. I will look into this another time, but I have to say that I do not personally notice any problems with colour perception under these particular LED lamps, and can still read resistor colour codes for example (even if I do need a magnifying glass to do so these days).
Is that scientific enough for everybody?
For the uninitiated: GLS = General Lighting Service, ie normal tungsten-filament incandescent lighting where the light is produced by a hot glowing wire together with a great deal of energy wasted as heat; LED = Light Emitting Diode, light produced by an electronics device with relatively little energy wasted in the form of heat; CFL = Compact Fluorescent Lamp, light produced by a miniaturised fluorescent tube like the traditional "strip light", again with relatively little waste heat but with a short period before the lamp reaches full brightness. Fluorescent tubes create light by using a phosphor powder coating inside the tube to convert the UV from the electrical arc inside into visible light.
Clockwise from 1 o/c: shadow of the 7W LED; 8W CFL, 40W GLS.
The point of the shadow photos is that they provide a means to compare the illumination from multiple light sources, and even measure the relative intensity of two light sources with a ruler being the only calibrated standard necessary. If one wanted to measure the relative brightnesses of two sources, one would move one of the sources closer or further away from the screen until the two shadows were the same darkness, and then the relative intensities of the sources can be determined from their relative distances and the inverse square law. Comparing the shadows to achieve the same darknesses can be tricky if the sources have different spectra (ie colours).
In these cases, the shadowgraphs are only used for comparison. In the above, the LED source clearly creates the darker shadow and therefore is by far the strongest source in the forward direction. The CFL comes second, with the GLS a close third.
The overall light output of each lamp is spread around the room however, and not just in the forward direction. GLS and CFL have a more-or-less full spherical distribution, with just the large base of the CFL creating a shadow in the reverse direction. LEDs mostly emit in the forward direction (a hemisphere, with a drop-off towards the edges), but these particular lamps have (maybe) multiple emitters arranged pointing in different directions behind a diffuser so that the output is uniform in all directions (except behind, where typically light is not needed anyway). Because of these differences in distribution, it is difficult to compare the total light output from these sources (although it would be possible, either by measuring over the whole sphere and integrating, or by arranging reflectors to make all the light output from any source go in the forward direction).
With all that in mind however, in my opinion the total output of the 7W LED lamp still exceeds the total output of the 8W CFL by a small margin, and the total output of the 40W GLS by a significant margin.
As far as colour rendering goes, maybe somebody has a spectrometer they can lend me. Perhaps there are standard colour charts - paint manufacturers' colour swatches might do. The sort of chart opticians use to diagnose colour blindness might work too. I will look into this another time, but I have to say that I do not personally notice any problems with colour perception under these particular LED lamps, and can still read resistor colour codes for example (even if I do need a magnifying glass to do so these days).
Is that scientific enough for everybody?
OP
Deleted member 473
No! A searchlight would give a higher intensity in one direction, but would you want to light a room that way? Measuring light intensity in the direction of a camera is neither here nor there, it is total lumen output that matters.
There is hardly any difference between lumen output from cfl and led, I retract my statement above. What I should have, and meant to say, was that cfls give a better quality light. I am not sure that more leds would correct that. More would consume more watts, but still not improve quality.
The total light lumen output is actually quite easy to measure, without integration! BH was thinking out loud above, I guess.
As for being anti-led, every bulb in our house is led, apart from those in our cooker.
Finally, and at present, it is difficult to justify leds on cost savings because cfls have improved so much and are so cheap. Also, premature led failures are worryingly common, and that may push things in favour of cfls on balance.
There is hardly any difference between lumen output from cfl and led, I retract my statement above. What I should have, and meant to say, was that cfls give a better quality light. I am not sure that more leds would correct that. More would consume more watts, but still not improve quality.
The total light lumen output is actually quite easy to measure, without integration! BH was thinking out loud above, I guess.
As for being anti-led, every bulb in our house is led, apart from those in our cooker.
Finally, and at present, it is difficult to justify leds on cost savings because cfls have improved so much and are so cheap. Also, premature led failures are worryingly common, and that may push things in favour of cfls on balance.
Black Hole
May contain traces of nut
Go on then, explain how.
I think I have adequately demonstrated that the LED lamp is emitting in all the directions that matter.
OP
Deleted member 473
OP
Deleted member 473
Rofl. An earlier effort from BH or just coincidence?
http://www.thesimpledollar.com/the-...bs-whats-the-best-deal-now-and-in-the-future/
http://www.thesimpledollar.com/the-...bs-whats-the-best-deal-now-and-in-the-future/