JoakimFlorence
Newly Enlightened
- Joined
- Jun 4, 2016
- Messages
- 194
Sylvania TruWave "bright white" (3500K)
White LED light usually has a narrow wavelength of blue. In a spectral graph, this typically shows up as a tall spike of blue at about 450nm. This defines the character of typical LED, preventing the light from feeling as "natural" as some other light sources, and leading to some limitations in color rendering ability in the deep indigo and azure/cyan color areas.
Newer technology violet emitter white LEDs are one strategy that can be used to address this issue, albeit with a sacrifice in efficiency (as well as violet emitters being more expensive than blue emitters used in standard white LED), with the blue light being given off by a special phosphor.
But there is another LED technology that can attempt to address this issue, and that is broader-band blue LED, which emits a wider range of blue wavelengths than a normal blue LED. This has been discussed years ago in this forum, but it has now become incorporated into mainstream commercial products. Two retrofit LED bulbs that use this technology are the Philips "Ultra Definition", and the Sylvania "TruWave". The blue emitters use "quantum well" technology. An official spectral graph of Sylvania's Truwave product shows the tallest blue spike at what appears to be 430 or 440nm, another second slightly smaller spike at around 450nm, and then a third medium-sized spike at what appears to be 470 or 475nm, which partially overlaps into the green wavelength area, creating a relatively continuous spectrum (at least according to the graph, though I have reason to be somewhat skeptical).
diagram of spectral graph can be seen here:
related older threads:
Is violet really the best way to go? (Jun 5, 2016 )
98 CRI from BLUE emitter (Nov 25, 2014 )
(mentions "Spectrafill" technology by Electrospell in post #8, first announcement of a broadband blue LED emitter)
picture of product:
I decided to test the "TruWave" bulb to be able to evaluate the quality of the light, to provide a subjective description of it for the readers in this forum, and write a review.
The Sylvania TruWave was available in "Bright White", which I had mistakenly assumed would be 3000K in color temperature. It turned out that their "Bright White" version is actually 3500K. This is an unusual color temperature offering, as far as LED bulbs go.
I had decided to go with an intermediate color temperature because I thought 5000K would be too extreme, I would not be able to evaluate how natural that light felt very well, while on the other hand, with 2700K I was worried that the blue would not be a prominent enough part of the spectrum, and that is why I wanted to get this bulb, to evaluate how its special blue wavelengths affect the feel of the light.
Here is description of the light:
The 3500K color temperature looks very bright brilliant white and "clean". (This is indoors at night) The light feels very "white". (Maybe a little like one of those super "energy saver" halogen bulbs that is designed to push the color temperature all the way up to 3000K but doesn't end up lasting very long as result)
In appearance, the color rendering appears to me to look like exactly 90 CRI, no more, no less. Warm colors look noticeably less alive and saturated than another 91-93 CRI (3500K) LED lamp I have.
The CRI is "good enough" for most purposes though. Of course 90 CRI is a little bit better than the standard retrofit LED bulb. Fine print on the packaging claims it has improved color rendering compared to other 90 CRI LED lamps, which is probably true, since presumably it's basically using 90 CRI type phosphor but just has improved coverage in certain less usual color areas owing to the nature of the different blue wavelengths.
There is something strange feeling about the quality of the light. Objects under the light appear more detailed and higher definition, yet the light is also harsher.
Trying to describe the exact feel of the light, I would say the light feels like a mix of a 96 CRI (LED) emitter and metal halide. (I should clarify that, by that statement I do not mean to imply anything about color rendering or color temperature)
Maybe almost a little like the light of ceramic metal halide, if some of that were also mixed in.
Or another way to put it, I would say the light almost kind of looks like a three-way mix of LED, fluorescent, and a 3000K halogen incandescent, (I mean the type of halogen that has very white crisp clear light but also is just a little bit harsh, compared to 2700-2900K incandescent).
(Even that description is not entirely accurate, I'm afraid, since the blue light is neither really quite as "hollow" and out of focus as fluorescent, nor quite as entirely in-focus as halogen. In other words I'd say the blue light is more like some other light sources besides normal LED, but neither is it really precisely like what you'd get if you mixed those other light sources)
I did make reference to 96 CRI light, because I have some Oslon 96 CRI emitters and the quality of the light seems noticeably a little more clear, in-focus, and "natural feeling" than the light from other LED sources. Well, the TruWave kind of goes a little notch above this (though still not quite to the level of violet emitter).
Looking at the spectrum of the light through a diffraction grating, I can still see a gap between the blue and the green. The difference is that the blue seems a bit wider, ranging into the deeper 430-440nm violet-blue and a little into the 470nm "ice blue" territory, though the very light whitish 485-490nm "cyan blue" is still almost completely absent.
This does make me skeptical about the company's graph being accurate. I would guess that the intensity of wavelengths between 480 and 490nm might only be 30 or 40% of the intensity of the rest of the blue, conflicting with the company's graph that only shows only a shallow 20% dip in that area.
When I say the light is "harsher", it almost hurts my eyes after looking at the bulb for two minutes. An experience I do not have with normal LED, but which I do have with fluorescent. Although I'd say it is only maybe 45% as bad as a comparable compact fluorescent bulb (of equal color temperature).
This harshness is not so different from the light peaking in through a window on a completely overcast day with grey skies from the cloud cover.
The marketing hype claims this new technology has "reduced glare" and is "easier on the eyes", but it is not (in my opinion), rather it is actually worse.
However, there is no denying that the light also feels a little "higher definition" than the light from regular LED light, and I would say this effect is almost noticeably so. When reading small black print against a white background, the print appears a little "clearer" to me, with the edges of the print more defined. Whereas under regular LED light, fine print can appear almost just a little bit out of focus, with less clear edges between the black and white areas.
Both of these attributes are what one would expect from including a little bit of a wider range of blue wavelengths.
In terms of color rendering, I did notice the light seemed to do a little bit of a better job rendering both deep royal blues and lighter blue teal colors. It made blue colors appear a little more natural. I would not say it was extremely noticeable, but neither would I say it was hard to see if someone was trying to pay attention to that specific difference and had it pointed out to them. I had a teal-blue color in my shoes that looked noticeably brighter and lively under the TruWave light, but looked dead and less bright under normal LED light (which was 90 CRI, 3000K).
White LED light usually has a narrow wavelength of blue. In a spectral graph, this typically shows up as a tall spike of blue at about 450nm. This defines the character of typical LED, preventing the light from feeling as "natural" as some other light sources, and leading to some limitations in color rendering ability in the deep indigo and azure/cyan color areas.
Newer technology violet emitter white LEDs are one strategy that can be used to address this issue, albeit with a sacrifice in efficiency (as well as violet emitters being more expensive than blue emitters used in standard white LED), with the blue light being given off by a special phosphor.
But there is another LED technology that can attempt to address this issue, and that is broader-band blue LED, which emits a wider range of blue wavelengths than a normal blue LED. This has been discussed years ago in this forum, but it has now become incorporated into mainstream commercial products. Two retrofit LED bulbs that use this technology are the Philips "Ultra Definition", and the Sylvania "TruWave". The blue emitters use "quantum well" technology. An official spectral graph of Sylvania's Truwave product shows the tallest blue spike at what appears to be 430 or 440nm, another second slightly smaller spike at around 450nm, and then a third medium-sized spike at what appears to be 470 or 475nm, which partially overlaps into the green wavelength area, creating a relatively continuous spectrum (at least according to the graph, though I have reason to be somewhat skeptical).
diagram of spectral graph can be seen here:
related older threads:
Is violet really the best way to go? (Jun 5, 2016 )
98 CRI from BLUE emitter (Nov 25, 2014 )
(mentions "Spectrafill" technology by Electrospell in post #8, first announcement of a broadband blue LED emitter)
picture of product:
I decided to test the "TruWave" bulb to be able to evaluate the quality of the light, to provide a subjective description of it for the readers in this forum, and write a review.
The Sylvania TruWave was available in "Bright White", which I had mistakenly assumed would be 3000K in color temperature. It turned out that their "Bright White" version is actually 3500K. This is an unusual color temperature offering, as far as LED bulbs go.
I had decided to go with an intermediate color temperature because I thought 5000K would be too extreme, I would not be able to evaluate how natural that light felt very well, while on the other hand, with 2700K I was worried that the blue would not be a prominent enough part of the spectrum, and that is why I wanted to get this bulb, to evaluate how its special blue wavelengths affect the feel of the light.
Here is description of the light:
The 3500K color temperature looks very bright brilliant white and "clean". (This is indoors at night) The light feels very "white". (Maybe a little like one of those super "energy saver" halogen bulbs that is designed to push the color temperature all the way up to 3000K but doesn't end up lasting very long as result)
In appearance, the color rendering appears to me to look like exactly 90 CRI, no more, no less. Warm colors look noticeably less alive and saturated than another 91-93 CRI (3500K) LED lamp I have.
The CRI is "good enough" for most purposes though. Of course 90 CRI is a little bit better than the standard retrofit LED bulb. Fine print on the packaging claims it has improved color rendering compared to other 90 CRI LED lamps, which is probably true, since presumably it's basically using 90 CRI type phosphor but just has improved coverage in certain less usual color areas owing to the nature of the different blue wavelengths.
There is something strange feeling about the quality of the light. Objects under the light appear more detailed and higher definition, yet the light is also harsher.
Trying to describe the exact feel of the light, I would say the light feels like a mix of a 96 CRI (LED) emitter and metal halide. (I should clarify that, by that statement I do not mean to imply anything about color rendering or color temperature)
Maybe almost a little like the light of ceramic metal halide, if some of that were also mixed in.
Or another way to put it, I would say the light almost kind of looks like a three-way mix of LED, fluorescent, and a 3000K halogen incandescent, (I mean the type of halogen that has very white crisp clear light but also is just a little bit harsh, compared to 2700-2900K incandescent).
(Even that description is not entirely accurate, I'm afraid, since the blue light is neither really quite as "hollow" and out of focus as fluorescent, nor quite as entirely in-focus as halogen. In other words I'd say the blue light is more like some other light sources besides normal LED, but neither is it really precisely like what you'd get if you mixed those other light sources)
I did make reference to 96 CRI light, because I have some Oslon 96 CRI emitters and the quality of the light seems noticeably a little more clear, in-focus, and "natural feeling" than the light from other LED sources. Well, the TruWave kind of goes a little notch above this (though still not quite to the level of violet emitter).
Looking at the spectrum of the light through a diffraction grating, I can still see a gap between the blue and the green. The difference is that the blue seems a bit wider, ranging into the deeper 430-440nm violet-blue and a little into the 470nm "ice blue" territory, though the very light whitish 485-490nm "cyan blue" is still almost completely absent.
This does make me skeptical about the company's graph being accurate. I would guess that the intensity of wavelengths between 480 and 490nm might only be 30 or 40% of the intensity of the rest of the blue, conflicting with the company's graph that only shows only a shallow 20% dip in that area.
When I say the light is "harsher", it almost hurts my eyes after looking at the bulb for two minutes. An experience I do not have with normal LED, but which I do have with fluorescent. Although I'd say it is only maybe 45% as bad as a comparable compact fluorescent bulb (of equal color temperature).
This harshness is not so different from the light peaking in through a window on a completely overcast day with grey skies from the cloud cover.
The marketing hype claims this new technology has "reduced glare" and is "easier on the eyes", but it is not (in my opinion), rather it is actually worse.
However, there is no denying that the light also feels a little "higher definition" than the light from regular LED light, and I would say this effect is almost noticeably so. When reading small black print against a white background, the print appears a little "clearer" to me, with the edges of the print more defined. Whereas under regular LED light, fine print can appear almost just a little bit out of focus, with less clear edges between the black and white areas.
Both of these attributes are what one would expect from including a little bit of a wider range of blue wavelengths.
In terms of color rendering, I did notice the light seemed to do a little bit of a better job rendering both deep royal blues and lighter blue teal colors. It made blue colors appear a little more natural. I would not say it was extremely noticeable, but neither would I say it was hard to see if someone was trying to pay attention to that specific difference and had it pointed out to them. I had a teal-blue color in my shoes that looked noticeably brighter and lively under the TruWave light, but looked dead and less bright under normal LED light (which was 90 CRI, 3000K).
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