A new accessory is fast-becoming a must-have for those who like to trip the proverbial light fantastic. Everyone today wants part of the LED pie. Invented in the 1920s, the light emitting diode (LED) has stepped off the entertainment circuit and surged into the daily life. Once considered to be the domain of game scoreboards, mobile phone displays and decorative lighting, LED lighting is now on the cusp of becoming commonplace, as LEDs drastically reduce energy consumption and carbon dioxide emissions. Being twice more efficient than compact fluorescent bulbs, LEDs are compatible with dimmer switches, contain no toxic elements, and last long, LEDs have now begin to adorn many more houses, offices and even light the way not just by our cars but also our streetlights. As someone aptly put it, ?It is a fit-and-forget-lighting.?
Keith D?Silva, a chemical engineer, sheds light on the fact that LEDs basically emit light when an electric current is passed through them. ?The colour of light depends on the semi conductor material and not the colour of the casing (plastic body). LEDs are available in red, orange, amber, yellow, green, blue and white. These days you even get tri-colour LEDs, which are, essentially, two LEDs packed in one body,? he adds.
?The applications of LEDs are many,? says Eddie De Souza, Production Manager, Star Cruises. ?Right from being a replacement for conventional sources of lighting, LED lighting fixtures can be made in small, discreet packages, which suit applications, where size and brightness are important.?
LEDs are very quick in displaying pictures, graphics or movies. The images are more crisp and clean compared to that of regular plasma?s and LCDs. They repixilate graphics and display them accordingly. In theatre, production shows and concerts, LEDs have taken over the projector. ?LED setups primarily come in the form of panels, which are simple to operate through a console or a laptop and have software to calibrate the lights. This customisation of LEDs helps bring reality to the stage. In fact, from just a panel, the LED has gone on to become an intelligent moving head,? adds De Souza. In India, Philips is the only manufacturers that supply LEDs for the home segment. The reasons for LEDs supplanting incandescent and compact fluorescent bulbs have more to do with the inefficiency of traditional sources of lighting. LEDs use a fraction of the power of a normal light bulb, thus consuming less power. They also produce a high degree of brightness.
Catching the eye
But there is a flipside too. LEDs are expensive at the moment. But as they are put to more commercial use, the price will stabilise within the next two-three years. Experts also warn that the scuttle to make cheaper LED lights may lead to poorly made products, which could expunge the technology?s natural advantage. ?As LEDs gain popularity,? says D?souza, ?Chinese products or other cheap brands threaten to eat into it?s professional market share.?
Lighting is also a concern for photographers. The trouble with most light sources is that heat is produced in equal amounts, if not more. Photographer David Desouza elucidates how LEDs help in overcoming these challenges. ?Colour temperature is important in image projection and photography, where a colour temperature of approximately 5,500 degrees Kelvin is the requisite to match ?daylight? film emulsions. LEDs can thus be put together as a bank of lights for soft light or arranged in clusters for focus and can be programmed to produce any colour required, including resembling daylight and also to white light, which is important in photography.?
Home solutions
In the home space, reading lamps, house lighting fixtures, worship lamps and ambience lights are being replaced with LEDs. Even ceilings are being fitted with LEDs to give it a starry-night effect. Architect and interior designer Keith Singh adds, ?In India, this technology has not yet caught on completely for home usage. So people use them more as back lighting for fountains or lighting their front porches or in their gardens. But it won?t be long before we begin to use LEDs for daily lighting.? LEDs score over other forms of lighting simply because they produce very little heat. Desouza gives the example of a firefly. ?Scientists have tried to emulate a firefly, as it is the most efficient source of light. It produces absolutely no heat with the light it gives out.? If scientists do manage to do this, we just may have discovered fire for the second time.
But, for now, LEDs seem to be illuminating the path towards that more energy-efficient future.