Which projector to choose: laser, LED or a lamp one?
Until recently, projectors were used mainly in cinemas or for business events. But now more and more people are choosing a projector for use at home or for outdoor projection.
There are a lot of advantages of a projector over a TV set. But we'll talk about that in another post.
Today we will focus on choosing a light source inside your projector because this is what forms the beam which -- after processing -- you see on your screen as an image. Let's zoom in now on three types of projectors: a lamp, LED and a laser one.
Lamp projector (LCD)
This type of a projector is based on a transmissive LCD matrix. Such devices resemble ordinary film overhead projectors. But there is a difference. The image projected onto the external screen is formed when the light flux emitted by the lamp passes not through the slide, but through a liquid crystal panel which consists of many electrically controlled elements - pixels. The principle of their operation is simple and the price is really affordable. Yet this technology has many disadvantages.
Poor picture quality: Compared to other light sources, which we will discuss below, this technology has poorer color rendition and less image detail
Lamp resource: 1,000 – 6,000 hours depending on the manufacturer
Picture burn-in: Throughout the lamp's life, its brightness gradually grows dimmer
Long startup time: Lamp projector takes about 3 minutes to start, and 10-20 minutes to reach its full brightness
Low fault tolerance: The lamp gets quite hot, which requires a reliable cooling solution. It is highly recommended to not disconnect this type of projector from the power supply, as this may cause instant lamp failure and sometimes even an explosion. Such a projector should be turned off ONLY with the power button on, and disconnected from the mains ONLY after a proper LED indication and once the cooling fan is turned off
Large size and weight
High energy consumption
Light-emitting diodes (LED) projector
LED was the first solid state light source used in projectors. Despite the fact that LED projectors use a principle similar to laser, marketers have not yet called this projector "laser". It is based on three LEDs: red, blue, and green. Through a system of optical lenses, they go to a special DMD chip which acts as a matrix, reflecting light from the three LEDs using millions of micromirrors, through the lens, after which the image is formed on the screen.
Long lamp life: Up to 20,000 hours
Better resistance to unexpected power outages
The cost is higher than in a lamp projector
Relatively low brightness (1000 -1200 ANSILm)
Incomplete transmission of yellow tones
Limited maximum image size
Noise level during operation, which often exceeds 35 dB
It takes time to reach maximum brightness
The picture quality in LED projectors is better than in projectors with a classic lamp, but it is much inferior to the projectors that we will discuss below.
With this technology, just one, blue laser diode, is used as a light source. A single laser beam is directed onto a complex optical design using rotating elements that separates it into red, green and blue. This beam falls on the DLP matrix which is based on the same DMD matrix that we talked about above. This matrix transmits the image through the lens onto your projection screen.
Long-life service of the light source (10000-2000 hours)
Extended time period between each maintenance (cleaning) of the projector
Even better resistance to sudden power outages -- compared to lamp and LED projectors
High picture quality
Larger image size
Cost (more expensive than lamp and LED projectors)
It still takes time to reach maximum brightness
Picture quality and brightness are inferior to laser projectors
Despite the fact that DLP projectors use a laser light-emitting diode, it is not called a Laser projector due to the nature of the technology and marketing considerations.
The specs of this type of projectors are very similar to DLP projectors.
RGB Laser projector
All projectors that manufacturers market as Laser use RGB Laser technology. A pure laser -- also known as an RGB laser -- generates light directly from three individual red, green and blue lasers. Then, the bunch of these falls on the same DMD chip and displays a picture through the lens onto your screen.
The main advantage of the RGB system is that thanks to this solution we finally achieve really high quality parameters such as brightness, wide color gamut covering the BT2020 space, contrast ratio and dynamic range. Standard lamp projectors pale in front of the RGB Laser ones.
The best color and clarity available today
High image brightness
Ability to provide large projected image size
Instant switch on
Emergency switch off does not harm the light source
Less strict requirements for the projection surface onto which the image is projected
High uniformity of white
Low noise level
Positioning flexibility: the projector can be fixed at any angle
Energy efficiency that is due to the fact that the brightness of the laser projector can be precisely "tuned" only to the required wavelength of red, green and blue colors. No energy is wasted on unnecessary frequencies.
Cost. Currently, laser projectors are the most expensive of all on the market. Despite the serial production of laser projectors for the last 10 years, the price has not dropped to the figures sane in the understanding of an average home movie fan.
Flickering source. This factor will not be very noticeable to an average AV consumer. However, in some tasks this effect can be significant when choosing this type of projector.
Some colors are unnatural. Yes, our eye can perceive a picture overflowing with colors which can, on the contrary, alienate it from the real one. In some models, quite sharp transitions in the color palette are noted, which can be annoying during prolonged viewing. But different manufacturers started to use technologies that help reduce this effect.
To wrap up, we want to leave you with the idea that the best currently available consumer projectors are laser devices. But for many, their price may be too high. If your budget allows, buy them and you will get the best picture in the light of the latest technologies for a long time to enjoy.
If you are on a budget, but want to have a high-quality picture, DLP is your choice.
Most people choose DLP projectors for their home theaters as a good price / quality ratio.