I don't know about others but I am uncomfortable with this and I tried to find what could be the reason for this. Possibly the problem could be different for others and the reasons could be different. These all depend upon the exposure of us and our earlier generation. However, wondering about things is the main motivation behind this blog.
So the thought is: Over the generations we got used to sunlight (spectrum). As we know white light is a mixture of various colors.
Now if we look at Tubelight specifications: a temperature is mentioned. Now from Planck's theory on Black body radiation, if the spectrum is same as that of sun's light, we feel the light as comfortable because it has that similar amount of colors mixing to produce white light as in sun light.
Because over the years our sensors (eye's cones & rods) got calibrated well to this detection level (of that spectrum range). If the temperature mentioned is different, you will technically see some color of light more dominating.
Now if we look at LED street lights, the phenomenon is that we pass current and electrons get recombined to give flash of light (at a frequency we can't distinguish between continuous or discrete). So the light has some particular wavelength (may be green/blue/something..) but not white because we can get white only through the combination of different colors. So they have small LEDs packed together which give red, green, blue on whose combination white light is seen. You can learn a bit more on LEDs in this link: white light using LED
The problem with this is that the resultant spectrum is "whether it is same as that of the sun light ?" So as long as the resultant spectrum is same as sun light spectrum (for people who are more habituated to day light), the eyes feel comfortable.
Any suggestions to improve the article are welcome..!
So what we can say about LED TV...now a days many people are going for LED TV might because of less power consumption + clarity of picture, right?..so here how SUN's spectrum plays a role...
ReplyDeleteSun's spectrum has been the only source about light in the theories we use in engineering. The idea about LED TVs being better is largely because of the fact that they are active sources[no backlight-less consumption - better picture quality is questionable]. The spectral differences from sources which have the same color values[i will be killed by a lot of color scientists for using color here] can only be perceived if the light gets reflected from an object. Otherwise it is pretty easy to fool the eyes, if we are looking at the source directly. The case Vamshi discussed here is due to the fact that he perceives the light reflected off from different surfaces, I assume he is not talking about staring into the LED street lights :)
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