LED light bulb comparative review

I find that I have accumulated a number of LED light bulbs and after doing the 3M review, decided to just photograph them all under somewhat controlled conditions, mostly to get a sense of color rendition. I say "somewhat" controlled since I did not use a particularly precise camera nor did I do this in absolute darkness.



The setup

The scene lit with ambient lighting from 4x 32W T8 floros behind (~6000K if I recall), a proprietary T5 circline fixture to the left (probably also ~6000K), and some sunlight from the windows ahead and behind. This is a decent representation of color - camera set to auto white balance, no flash. I would like to thank my "assistant" in the background for his considerable restraint not "helping" in any way whatsoever.




(Most Of) The Contenders

Control Samples

• 60W "long life" incandescent (clearly, this bulb has lived a hard life)
• GE 40W equivalent warm white CFL

The LED's

• Unknown LSG Warm White "40W" : 8W, 425lm, 3000K
• Philips AmbientLED "60W" : 12.5W, 800lm, 2700K
• 3M Advanced LED "60W" : 13.5W, 800lm, 4000K
• EcoSmart (LSG) Cool White "40W" " 8W, 510lm, 5000K
• Cree Cool White "60W" : 9W, 800lm, 5000K
• UtiliTech PRO "40W" (not shown above) : 7.5W, 450lm, 2700K

Methodology
All photography performed with a handheld cellphone camera (Samsung Galaxy Nexus) using the stock camera application. Exposure was set to auto on all photos.

I took 5 photos for each sample:

• The bulb itself, auto white balance (WB), auto flash (most of these were taken in relative darkness between bulb swaps)
• The bulb illuminated in the fixture, auto WB, auto flash (color rendition on these is all over the place, thus not representative
• Test subject with incandescent WB
• Test subject with florescent WB
• Test subject with sunlight WB - generally not at all representative

Test subject is A Day with Wilbur Robinson, chosen because it was handy and has a fairly broad spectrum of colors - albeit a bit heavy on blue and green and somewhat faded:






Control Samples
Incandescent
I begin with the only incandescent I could find, which happened to be a generic 60W long life bulb that's probably as old as the oven vent hood it lives in (around 20 years). This is hardly the best incandescent around, but should suffice for comparison on color rendering.

The bulb itself has some accumulate crud from 20 years of living in an oven vent hood. Not claiming this is the best incandescent out there, just using it for color rendition purposes.
Illuminating the fixture.


Incandescent WB - unsurprisingly, this is the best representation of how it renders color.
Florescent
sunlight


CFL
GE warm white "40W" equivalent CFL, circa 2008-2009 vintage. Been using these in a vanity fixture in the guest bathroom for years without complaint.

In its spiral glory. In the fixture.


Florescent WB - unsurprisingly, this is the best representation of how it renders color.
Incandescent
Sunlight




Warm White LED's
LSG 3000K
This is a replacement for a recalled EcoSmart (LSG) bulb I bought in 2011. I prefer the light quality on this over predecessor and the other 2700K bulbs I have. It is extremely directional, throwing very little light behind it. I'm finding that this bulb is improving my opinion of high-temperature "warm" tints - would like to see some option in the 3000K-4000K range from manufacturers.

The bulb itself, illuminating the fixture.


Florescent WB is the most repsentative.
Incandescent
Sunlight


Philips AmbientLED
Probably one of the most familiar LED light bulbs out there, this bulb has a few hundred hours' use on it and has gone from a desk lamp (where it was too bright) to the permanent resident of this fixture.

The bulb itself, illuminating the fixture.


Incandescent WB is the most representative.
Florescent
Sunlight


UtiliTech PRO
I bought two of these on sale at Lowes in 2011. One has been running 24/7 (with perhaps 48 hours' interspersed downtime) for a bit more than two years in a mostly-enclosed fixture; the other I gave to a friend. I believe that it uses discrete intermediate-power SMD LED's rather than the power LED's and array packages that the other bulbs use.

The bulb itself, illuminating the fixture


Incandescent WB is the most representative.
Florescent
Sunlight (one of the closest sunlight representations of how I perceived it)




Cool White LED's
3M Advanced LED "60W"
My most recent acquisition, the 3M is one of the more unusual options out there. It utilizes fancy fiber optic light guides to achieve a fairly uniform light distribution. It's also incredibly heavy. To my eyes, it's not very far removed from the 5000K bulbs I also have. I did a review of it yesterday.

The bulb itself, illuminating the fixture.


Florescent WB is the most representative.
Incandescent
Sunlight


EcoSmart (LSG) "40W"
I have a pair of these - one in a desk lamp, the other in a porch light. In the desk lamp, it makes it so much easier to read and concentrate than the previous occupant (recalled LSG 2700K "40W"). In the porch light, it doesn't attract anywhere near as many insects as the incandescents and florescents used to - in addition to being a more pleasing color that better matches the ~4000K LED fixtures I have lighting up the front driveway.

The bulb itself, illuminating the fixture.


Florescent WB is the most representative, although I find it is probably the most "off" - auto WB is true to life, but using that image destroys the semi-controlled aspect of this experiment.
Incandescent
Sunlight (not terribly far off)


Cree "60W"
A somewhat recent acquisition, I have 3 of these in a ceiling fan light fixture in my office.

The bulb itself, lighting the fixture.


Florescent WB is the most representative.
Incandescent
Sunlight

I really appreciate that you went to all the trouble to do a comparison and post the results online. But your test had a few big shortcomings.

That incandescent bulb you used was just pitiful. Really?!? Just look at it! :shakehead
Not only that, but being a 130v rated long-life bulb, we would expect that the color temperature would be shifted well into the orange. Incandescent may have a 100 CRI by definition, but the color rendering of those greens and blues is still going to be terrible if the filament temperature is below 2600K.
Looks like the bulb is severely blackened from decades of use, I wonder how that might be affecting the spectrum.

You could not find any regular incandescent bulbs? Were you trying to make incandescent bulbs look bad?

Halogen replacement bulbs are being commonly sold in stores. Could you have not tried one of them?
Halogen should have excellent color rendering, and would make a great gold standard to compare all the other light sources to.

idleprocess said:

Test subject is A Day with Wilbur Robinson, chosen because it was handy and has a fairly broad spectrum of colors - albeit a bit heavy on blue and green and somewhat faded:

Click to expand...

If you were trying to demonstrate color rendering, using an already faded subject was probably not the best choice. Poor color rendering can make some colors look greyish, so how are we to know if the dull greyish colors are due to aging of the paper or the light source illuminating it in the picture?

Anders, what is your point really?

Did idleprocess anywhere in his post slag incandescent? No. All he did was post some pictures to show how this image may look w.r.t. the setting on his camera.

Getting into a discussion about the image used, the incan bulb, etc. is meaningless.

Any photo based comparison of light bulbs is just that .... a photo based comparison and really says more about white balancing on the camera at time then the light source.

I doubt many of the people reading this have ever seen the picture in person so we have no frame of reference (a picture in bright real sunlight would be a nice reference).

Our eyes will adapt to whatever light source we are using, so fixed white balance on a camera is just that, a fixed setting that does not really relate to how our eyes would perceive the lighting. Letting the camera (or post processing s/w) auto white balance may be more representative of how our eyes would perceive the lighting (after an adaptation period), but that was not the goal of the idleprocess in his post.

Semiman

Anders:

If you walk away with one thing from this review, let the next sentence be it: This was not about incandescent bulbs - it was about the various LED bulbs I have accumulated. As my initial post states and your response make abundantly clear, the incandescent is not the best example nor even a typical example. I assume the readership here is intelligent enough to reach that conclusion.

At the last minute, I decided to include an incandescent and CFL. My choices for incandescent was said well-abused long-life bulb, some 25/40W appliance bulbs I was not eager to remove (oven, refrigerator, dryer), and some candelabra bulbs in another fixture that's rarely used and hard to get to.

I do not feel compelled to source some incandescents nor halogens that I'm never going to use.

As for the test subject - it was handy, flat (making for a more consistent photo), and has an OK color gamut. As opposed to "faded", I should have said "muted" since the colors don't quite pop like something with fullbright primary pigments would.

idleprocess said:

This was not about incandescent bulbs - it was about the various LED bulbs I have accumulated.

Click to expand...

I understand, but your pictures seem rather meaningless without a good control. How are we to know what those LED bulbs really look like? Obviously cameras are notoriously bad at accurately showing colors. To be honest, none of the colors in those pictures you posted look very vibrant.

This picture seemed to have the best color rendering (though it is a bit difficult to tell in these pictures), but you did not clearly label what the light source was:

idleprocess said:

Test subject is A Day with Wilbur Robinson, chosen because it was handy and has a fairly broad spectrum of colors - albeit a bit heavy on blue and green and somewhat faded:

Click to expand...

Anders Hoveland said:

I understand, but your pictures seem rather meaningless without a good control. How are we to know what those LED bulbs really look like? Obviously cameras are notoriously bad at accurately showing colors. To be honest, none of the colors in those pictures you posted look very vibrant.

Click to expand...

The rest of us can look at the first and third photos to get an idea of what the test subject looks like under the mixed sources I noted. You are free to improve upon the experiment yourself using your own time and resources.