OP
Deleted member 473
Doesn't this article seal it? The total visible light emitted is the total lumens.
https://en.m.wikipedia.org/wiki/Lumen_(unit)
https://en.m.wikipedia.org/wiki/Lumen_(unit)
Black Hole
May contain traces of nut
I think that's probably a good summary - only a proper examination of the subject will confirm it.
On that basis: lumens output per electrical watt input provides a measure of the efficiency* of a lamp, but I think lux is probably a better measure of its usefulness.
* The sources seem to prefer the term "efficacy", but I don't understand the distinction.
On that basis: lumens output per electrical watt input provides a measure of the efficiency* of a lamp, but I think lux is probably a better measure of its usefulness.
* The sources seem to prefer the term "efficacy", but I don't understand the distinction.
OP
Deleted member 473
MikeSh
Well-Known Member
Presumably lower voltage bulbs are more efficient at producing visible light. I don't know why but as they will have thicker filaments I'd guess that may have some effect on the function.
OP
Deleted member 473
Oh no!
https://www.cinema5d.com/tungsten-lighting-beats-led-efficiency-128/
I suppose they may not last long, though.
https://www.cinema5d.com/tungsten-lighting-beats-led-efficiency-128/
I suppose they may not last long, though.
Black Hole
May contain traces of nut
Ironic.
Pretty early in this thread I was bemoaning the non-uniform output of LED lamps compared with the GLS I wanted to replace. Unless it's a single-lamp fitting, the light distribution can be largely compensated by using a fitting which angles the lamps in complementary directions, but of course I'm too tight to consider entire new light fittings.
(BTW: I regularly pass a lighting showroom with all manner of weird modern lighting I wouldn't give house room nor have the space for, because of the artistic opportunities offered by distributing individual LED chips over a surface rather than as a replaceable module, but new regulations for repairability are going to shake all that up!)
The irony is that I have a couple of reflector bulbs where I want directed light with little overspill, one has failed, and now incandescent spots (or any other incandescent lamp) is unobtanium off the shelf. I bought a pair of cheap R50 SES form-factor LED lamps to plug the gap, but although they fit the fitting these do not perform the desired function of providing directed light.
In fact, I didn't even used to have standard R50s in those fittings, my preference was the narrower beam version with the bevelled edge, so the 180º spread of these LEDs is a bit of a shock.
af123 was extolling the virtue of reflector LEDs:
Pretty early in this thread I was bemoaning the non-uniform output of LED lamps compared with the GLS I wanted to replace. Unless it's a single-lamp fitting, the light distribution can be largely compensated by using a fitting which angles the lamps in complementary directions, but of course I'm too tight to consider entire new light fittings.
(BTW: I regularly pass a lighting showroom with all manner of weird modern lighting I wouldn't give house room nor have the space for, because of the artistic opportunities offered by distributing individual LED chips over a surface rather than as a replaceable module, but new regulations for repairability are going to shake all that up!)
The irony is that I have a couple of reflector bulbs where I want directed light with little overspill, one has failed, and now incandescent spots (or any other incandescent lamp) is unobtanium off the shelf. I bought a pair of cheap R50 SES form-factor LED lamps to plug the gap, but although they fit the fitting these do not perform the desired function of providing directed light.
In fact, I didn't even used to have standard R50s in those fittings, my preference was the narrower beam version with the bevelled edge, so the 180º spread of these LEDs is a bit of a shock.
af123 was extolling the virtue of reflector LEDs:
...but that website no longer seems to be working. Any ideas?
Beam Angle Guide - The Lightbulb Co. UK
Choosing a Light Bulb with the correct beam angle is very straightforward, and it will make all the difference when
www.thelightbulb.co.uk
Black Hole
May contain traces of nut
That site lists six R50 options, three of which are 110º+ and three 36º beam angle. Interesting.
(The site itself is slow and unresponsive on my bandwidth!)
(The site itself is slow and unresponsive on my bandwidth!)