The best (in the world in fact) flashlight
We chose a gift for the new year to the partners of the lighting company, found a flashlight with an unprecedentedly high color rendering index Ra (CRI) = 95.
Few people have a flashlight with a light of this quality, with laboratory-confirmed lighting characteristics and a ies-file. It was supposed to put our logo, put an extended passport and give good people.
Samples of Astrolux A01 flashlights have been purchased for ~ $ 10 each, given to the factory photometric laboratory. The spectrum was taken with a UPRTEK MK350N spectrometer with a valid Rostest calibration certificate. The light intensity curve and the luminous flux were measured with a goniophotometer (entered into the register of measuring instruments, reconciled with laboratories of the CREE and OSRAM companies).
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The color temperature is 5000 K. The color is white without shading, the deviation from the ACH curve is duv = 0.0005, which roughly corresponds to half the step of MacAdam. The overall color rendering index in the CRI metric is indeed Ra = 95.
The calculation of color in the metric TM30-21 showed Rf = 88 and Rg = 97.
KCC (light intensity curve) is concentrated, there is a halo.
The flashlight is turned on by turning the head. Repeated rotation of the head changes the modes of illumination: maximum; dimmer; still dimmer; strobe
For the maximum brightness mode, the manufacturer stated in the passport a luminous flux of 102 lm, however, direct measurement of three samples showed 60 lm, 55 lm and 50 lm. Moreover, the sample with a flow of 50 lm in the first two minutes gave 70 lm and then independently jumped into 50 lm mode. The sample ies file with a 55lm luminous flux can be downloaded from the link .
The head of the lantern is smooth, there are no projections that allow the torch to be put on the table so that some of the light goes out and dimly lights the room. Protection from rolling off the table has no body.
About the spectrum:
The color temperature of 5000K is the upper limit of neutral white light and is a good choice for color discrimination tasks. For reference, the color temperature of the “ideal” spectrum E with an equal share of all spectral components is 5450 K. And the recently approved, controversial, but legally valid document SP 52.13330.2016. NATURAL AND ARTIFICIAL LIGHTING contains a recommendation to use sources with a color temperature of 5000-6500K. color control with very high color discrimination requirements. "
The spectrum is continuous with a sufficient amount of red up to 650 nm.
The majority of LED street lamps sold today has Ra = 70..75, for rooms 80 ... 83. Better than Ra = 95, I personally did not see it, only I heard about box lights in “special” projects.
The color fidelity index Rf = 88 for the TM30-21 metric does not seem to be sky-high, it’s just good. The values ​​Rf = 88 and Rg = 97 mean that the colors of the illuminated surfaces practically do not differ from the colors under natural lighting in tone and saturation.
It can be said that the Nichia NVSW219C-R9050 diode used in the flashlight gives natural daylight "as if from a window".
About management:
Turning the flashlight on by turning the head requires two hands. Man is a two-handed being, it is wrong to select both for the task of turning on a flashlight, at least one hand must remain free for the main thing.
Turning your head is a vague way to turn it on! The button is good because it has two states - “on” and “off”, but the rotation has an infinite number of states, from which to choose the necessary ones is a task for a person who is not tired and not irritated.
About the stability of the light flux:
Okay, the samples would consistently give an actual amount of 50 lm instead of 102 lm, it was possible to re-issue the passport and correct the declared luminous flux. But how to relate to the independent switching to the mode of low light flux? If the user turned on the flashlight and does not turn it off, then the light is needed. There should not be a soulless piece of iron to make a decision for a person that there is enough light and less.
About modes:
Colleagues from the sky, who put a multi-mode driver in almost all flashlights, deserve blame. If I need light, I have to get it right away, and not through busting modes. And I do not need a little light, I need a maximum, I want to see, to hell with the battery savings. The flashlight should turn on immediately at full power, and turn off when it is no longer needed - I do not want to tune it and think about modes.
Stroboscopic mode is needed for cyclists who do not care about color rendition, but cheaper form of AA batteries is important in terms of Joule. If the flashlight under the AAA battery, and for cyclists is not intended, why a specific function?
About optics:
Why fuss narrowing KCC optics, if billions of users of flashlights in the phones checked the full suitability of the cosine KSS for most household purposes?
To see at once the whole field in which you are oriented is convenient and important. Concentrated KCC highlights only a small piece. The KCC can be narrowed down for special tasks, for example, if the lamp has a high luminous flux and it is necessary to beat the beam through the field. The logic of caring for a person with a pocket flashlight is simple - if you need more light, you need to give more light, and not constrict the CSS.
Maybe a halo around the main beam did, taking care of the person? In any case, a halo is a marriage, it divides the illuminated field into concentric circles, bringing essences into the observed scene unnecessarily.
About the case: The longitudinal edges are held on an inclined surface, but very weakly, literally touched with a hand, or the table is biased, tuk-tuk-tuk and reaches the edge. The developer’s inattention to detail is an alarming sign, expect surprises in other trifles.
About flashlights in general:
LED flashlights - a mysterious product. In 2008, for some reason I bought for $ 80 (then it was quite expensive) the O-light product, suggesting that I was buying some kind of “good” flashlight, without specifying what this might mean. Eight years have passed, the flashlight is alive and is a monument to my consumer stupidity. Nothing in it over the years, I have not found that would justify the price. And until now there are sellers who distinguish "good" flashlights from "cheap", but do not name specific significant differences other than price.
The Astrolux A01 flashlight, with all its flaws, has one indisputable advantage - high quality light. For example, this flashlight will fit the doctor to the patient in various interesting places.
About future:
In itself, the appearance of a flashlight with a good light is a significant event. LEDs began to be used first in flashlights, then hit the general lighting. Once the diodes with high color rendering began to be installed in the lanterns, one can also expect general lighting devices with light of normal quality.
The cost, for example, of a typical office lamp with Ra> 90 color rendition is only $ 5 higher than the analogue with the same luminous flux and efficiency, but with Ra> 80 color rendition. So why the consumer does not offer light of the highest quality for the $ 5 or even $ 10? I would pay, yes to no one, even my enterprise produces an entire vnutryanku with Ra> 80. And all because you, the consumers, value your quality of life low, you do not know about good light and do not ask.
It was decided that a flashlight, albeit with extremely high color rendition, but violating all the lighting principles as a gift from the lighting company is not suitable. Purchased samples donated to children, they will forgive. And partners of the company, as usual, received calendars for the new year.
About the author:
Anton Sharakshane, chief designer of the lighting company "LED-Effect", in the past, the chief editor of the magazine "Lighting" and the teacher of the department of lighting NRU MEI.
P.S:
One of the following planned posts: spectra and color rendition of various sources of illumination. Please suggest sources that you would be interested to measure. If there is an opportunity, come with your source to visit (Moscow, Tagansky district) - I will measure your spectrum, calculate and comment.
Few people have a flashlight with a light of this quality, with laboratory-confirmed lighting characteristics and a ies-file. It was supposed to put our logo, put an extended passport and give good people.
Methods
Samples of Astrolux A01 flashlights have been purchased for ~ $ 10 each, given to the factory photometric laboratory. The spectrum was taken with a UPRTEK MK350N spectrometer with a valid Rostest calibration certificate. The light intensity curve and the luminous flux were measured with a goniophotometer (entered into the register of measuring instruments, reconciled with laboratories of the CREE and OSRAM companies).
')
results
The color temperature is 5000 K. The color is white without shading, the deviation from the ACH curve is duv = 0.0005, which roughly corresponds to half the step of MacAdam. The overall color rendering index in the CRI metric is indeed Ra = 95.
The calculation of color in the metric TM30-21 showed Rf = 88 and Rg = 97.
KCC (light intensity curve) is concentrated, there is a halo.
The flashlight is turned on by turning the head. Repeated rotation of the head changes the modes of illumination: maximum; dimmer; still dimmer; strobe
For the maximum brightness mode, the manufacturer stated in the passport a luminous flux of 102 lm, however, direct measurement of three samples showed 60 lm, 55 lm and 50 lm. Moreover, the sample with a flow of 50 lm in the first two minutes gave 70 lm and then independently jumped into 50 lm mode. The sample ies file with a 55lm luminous flux can be downloaded from the link .
The head of the lantern is smooth, there are no projections that allow the torch to be put on the table so that some of the light goes out and dimly lights the room. Protection from rolling off the table has no body.
Discussion
About the spectrum:
The color temperature of 5000K is the upper limit of neutral white light and is a good choice for color discrimination tasks. For reference, the color temperature of the “ideal” spectrum E with an equal share of all spectral components is 5450 K. And the recently approved, controversial, but legally valid document SP 52.13330.2016. NATURAL AND ARTIFICIAL LIGHTING contains a recommendation to use sources with a color temperature of 5000-6500K. color control with very high color discrimination requirements. "
The spectrum is continuous with a sufficient amount of red up to 650 nm.
The majority of LED street lamps sold today has Ra = 70..75, for rooms 80 ... 83. Better than Ra = 95, I personally did not see it, only I heard about box lights in “special” projects.
The color fidelity index Rf = 88 for the TM30-21 metric does not seem to be sky-high, it’s just good. The values ​​Rf = 88 and Rg = 97 mean that the colors of the illuminated surfaces practically do not differ from the colors under natural lighting in tone and saturation.
It can be said that the Nichia NVSW219C-R9050 diode used in the flashlight gives natural daylight "as if from a window".
About management:
Turning the flashlight on by turning the head requires two hands. Man is a two-handed being, it is wrong to select both for the task of turning on a flashlight, at least one hand must remain free for the main thing.
Turning your head is a vague way to turn it on! The button is good because it has two states - “on” and “off”, but the rotation has an infinite number of states, from which to choose the necessary ones is a task for a person who is not tired and not irritated.
About the stability of the light flux:
Okay, the samples would consistently give an actual amount of 50 lm instead of 102 lm, it was possible to re-issue the passport and correct the declared luminous flux. But how to relate to the independent switching to the mode of low light flux? If the user turned on the flashlight and does not turn it off, then the light is needed. There should not be a soulless piece of iron to make a decision for a person that there is enough light and less.
About modes:
Colleagues from the sky, who put a multi-mode driver in almost all flashlights, deserve blame. If I need light, I have to get it right away, and not through busting modes. And I do not need a little light, I need a maximum, I want to see, to hell with the battery savings. The flashlight should turn on immediately at full power, and turn off when it is no longer needed - I do not want to tune it and think about modes.
Stroboscopic mode is needed for cyclists who do not care about color rendition, but cheaper form of AA batteries is important in terms of Joule. If the flashlight under the AAA battery, and for cyclists is not intended, why a specific function?
About optics:
Why fuss narrowing KCC optics, if billions of users of flashlights in the phones checked the full suitability of the cosine KSS for most household purposes?
To see at once the whole field in which you are oriented is convenient and important. Concentrated KCC highlights only a small piece. The KCC can be narrowed down for special tasks, for example, if the lamp has a high luminous flux and it is necessary to beat the beam through the field. The logic of caring for a person with a pocket flashlight is simple - if you need more light, you need to give more light, and not constrict the CSS.
Maybe a halo around the main beam did, taking care of the person? In any case, a halo is a marriage, it divides the illuminated field into concentric circles, bringing essences into the observed scene unnecessarily.
About the case: The longitudinal edges are held on an inclined surface, but very weakly, literally touched with a hand, or the table is biased, tuk-tuk-tuk and reaches the edge. The developer’s inattention to detail is an alarming sign, expect surprises in other trifles.
About flashlights in general:
LED flashlights - a mysterious product. In 2008, for some reason I bought for $ 80 (then it was quite expensive) the O-light product, suggesting that I was buying some kind of “good” flashlight, without specifying what this might mean. Eight years have passed, the flashlight is alive and is a monument to my consumer stupidity. Nothing in it over the years, I have not found that would justify the price. And until now there are sellers who distinguish "good" flashlights from "cheap", but do not name specific significant differences other than price.
The Astrolux A01 flashlight, with all its flaws, has one indisputable advantage - high quality light. For example, this flashlight will fit the doctor to the patient in various interesting places.
About future:
In itself, the appearance of a flashlight with a good light is a significant event. LEDs began to be used first in flashlights, then hit the general lighting. Once the diodes with high color rendering began to be installed in the lanterns, one can also expect general lighting devices with light of normal quality.
The cost, for example, of a typical office lamp with Ra> 90 color rendition is only $ 5 higher than the analogue with the same luminous flux and efficiency, but with Ra> 80 color rendition. So why the consumer does not offer light of the highest quality for the $ 5 or even $ 10? I would pay, yes to no one, even my enterprise produces an entire vnutryanku with Ra> 80. And all because you, the consumers, value your quality of life low, you do not know about good light and do not ask.
Conclusion
It was decided that a flashlight, albeit with extremely high color rendition, but violating all the lighting principles as a gift from the lighting company is not suitable. Purchased samples donated to children, they will forgive. And partners of the company, as usual, received calendars for the new year.
About the author:
Anton Sharakshane, chief designer of the lighting company "LED-Effect", in the past, the chief editor of the magazine "Lighting" and the teacher of the department of lighting NRU MEI.
P.S:
One of the following planned posts: spectra and color rendition of various sources of illumination. Please suggest sources that you would be interested to measure. If there is an opportunity, come with your source to visit (Moscow, Tagansky district) - I will measure your spectrum, calculate and comment.
Source: https://habr.com/ru/post/373089/
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