These days, no business/learning/classroom presentation is complete without the use of the projector. Digital projectors are making their presence felt be it in the corporate conference rooms, college lecture halls, and are moving into smaller classrooms. These are also being used in shopping malls, pubs and restaurants to give customers a unique experience in ambience as well as entertainment
TYPE OF DIGITAL PROJECTORS
Digital projectors are the modern replacement to more traditional transparency projectors (OHPs). Transparency projectors work by shining light through a semi-transparent material, such as slides or film. Digital projectors, by contrast, project a digital image directly from a computer or other digital devices through a lens on to a screen. There are three technologies, which are used, in digital projectors namely DLP (Digital Light Processing), LCD (Liquid Crystal Display) and Liquid Crystal On Silicon (LCOS).
LCD (Liquid Crystal Display)
LCD Projectors are the most popular and common type of Digital Projectors. First LCD Projector was launched by Epson in 1989 and later on Epson developed 3LCD projection technology, which is widely used in projectors and televisions. The price range starts from Rs 37,500 onwards.
DLP (Digital Light Processing)
DLP projection systems project images by reflecting light against hundreds of tiny mirrors known as digital micro mirror devices (DMD). That, along with the fact they are leading the weight loss trend in the projector market, makes them very appealing for presentations. DLP projectors also handle video images extremely well. DLP Projectors are prices at Rs 32,000 onwards.
LCOS (Liquid Crystal on Silicon)
The next generation of digital displays will use Liquid Crystal On Silicon (LCOS) technology. LCOS uses liquid crystals to control the path of light to micro mirrors. By combining elements of DLP and LCD projectors, LCOS projectors are able to create very high-resolution images with excellent colour saturation. Currently, only very high-end projection systems use this technology and are they are heavily priced. LCOS projectors are the most expensive of all projection technologies and price at Rs 2,02,000.
There is no easy answer to this question of what type of projection systems to purchase. LCDs tend to produce more highly saturated colours and sharper images; most DLP projectors offer deeper blacks and higher contrast. Depending on the resolution and size of your image, you may find LCD screens too pixilated. However if you tend to display very detailed images, you may find the softness of DLP projectors to be a problem. As a newer technology, DLP projectors were initially more expensive than similar LCD models, but that difference has largely disappeared.
PORTABILITY
There are four weight categories of projectors:
Ultra-portable:(Less Than 2.5 kg). These are best for the frequent traveller.
Portable: (2.5 kg - 7 kg). With additional weight, you generally get a higher level of brightness and more features. You can travel with these projectors.
Semi-portable: (7kg - 11 kg). These are primarily used for conference rooms and classrooms. Quite often they are ceiling mounted, but they can be moved from room to room without much difficulty.
Fixed installation: (Above 11 Kg). These projectors are heavy and used where portability is irrelevant. They generally have more facilities and features than the other projectors available in the market.
TYPE OF RESOLUTION
The best resolution for your projector is the resolution of the computer you intend to use with it. If you typically use a notebook with SVGA resolution, you will want a projector with the same native SVGA resolution to get the sharpest and cleanest image. In general, the higher the resolution, the more the projector will cost. Following are the types resolution available.
SVGA (800 x 600): An economical choice, and currently the second most popular resolution, SVGA is ideal for business PowerPoint style presentations with graphs, pie charts, and large text bullet items.
WVGA (854 x 480): This resolution displays by far the best images.
XGA (1,024 x 768): These higher resolution projectors are currently the most popular models on the market. They are more expensive than SVGA, and are better for displaying presentation material with intricate details such as excel sheets with numerical data, spreadsheets and text.
WXGA - Wide XGA (1280 x 720): These projectors are typically targeted for HDTV because they are designed with a 16:9 aspect ratio display; however, they can be used in most data and video applications.
SXGA (1280 x 1024): These high-resolution products are targeted for a wide range of high-end computers. They are used primarily for command and control, engineering and CAD/CAM applications where resolution of small details is important.
DISPLAY FEATURES
Illumination
Projector light output is measured in ANSI lumens or simply lumens. Higher the value, brighter the light output will be. In general, when choosing between projectors with similar specifications, the ones with a higher lumen rating will cost more. The advantage of a bright projector is that it can be used with the room lights on so people can interact with one another and take notes.
Contrast ratio
Contrast is the ratio between white and black. The larger the contrast ratio, the greater the ability of a projector to show subtle colour details and tolerate extraneous room light.
Aspect Ratio
A 4:3 display produces an image that is squarer, and a 16:9 ratio produces an image that is more panoramic in shape. For business use such as making presentations and viewing spreadsheets, 4:3 displays are still your best bet. You will still be able to take your projector home and watch movies during weekends. If you want to watch primarily wide screen DVDs and HDTV movie broadcasts, 16:9 is the right choice for you.
Uniformity (percentage)
Brightness uniformity is the percentage of brightness carried throughout a projected image. When an image is projected on the screen, you need to see how the brightness has spread on screen, particularly from centre to the corners of image. Brightness should be even all over the image. Some projectors have difficulty carrying brightness to the corners of the screen. The ideal number is about 85 percent uniformity for consistent image quality across the screen.
Digital zoom
Digital zoom helps increase or decrease images digitally. It also allows you to select one portion of the screen image and magnify it up to three times its original size from the handheld remote control. This is useful for technical or corporate presentations as it helps enhance the presentation content.
Zoom lens
This allows you to adjust the size of the image on the screen without having to move the projector back and forth.
Picture in Picture
Picture-in-picture feature offers the presenter the utility of two windows for two simultaneous projections, similar to the PIP feature in televisions. PIP is a useful feature for presentation where you have a live video projected on one screen along with relevant spreadsheets and figures shown on other screen simultaneously.
Digital keystone correction
Keystone correction feature in projectors allows images to be keystone corrected - basically to appear rectangular by adjusting and applying digital correction to the image. Ideally, a projector needs to be positioned at a level with or perpendicular to the screen in order to get the desired rectangular shape of the image. This feature is useful if one is required to make presentations at different locations where it is difficult to find the right place to mount a projector.
OTHER FEATURES
Built-in speakers
Most digital projectors come with in built speakers, which gives decent performance for limited audience. Projectors with built-in speakers are useful for presentation, which involve any type of audio sound. Projectors with built-in speakers are also beneficial for viewing movies. Look out for projectors with higher number of speakers.
Built-in DVD player
Some digital projectors come with built-in DVD players. It saves you on cost of buying a DVD player to watch movies and it also works as a mobile home theatre. It is also noticed that pictures projected from this type of projector are clearer as there is no wiring involved. Although this type of projector is a rarity, with the growing convergence needs of consumers, it won't be long before these projectors become popular. Be ready to shell out more moolah though.
Memory card slot
This slot allows you to insert PC/flash memory card to store presentations. Here, the presenter saves his presentation in compatible memory card which is small enough to travel with and easy to load on the projector. Memory card reader is of great use for computer-free presentations.
Remote control
The remote control is an external device that allows the user to use and control the projector without physically turning knobs or pressing buttons on the projector set itself. A small handheld device separate from the projector, it contains all projector controls such as volume, brightness, etc.
Wi-Fi
A projector Wi-Fi or wireless networking allows multiple computer users to wirelessly connect and display the computer information on a screen along with sharing. Wireless network projectors come with a software and wireless adapter, which needs to be installed in desired computers. Network projectors helps in reducing cost by letting multiple users to use, improves efficiency and economical use. Price range of digital projectors with Wi-Fi capability starts at Rs 81,400.
Voltage (volts)
If you have bought a projector abroad, you must use an adapter to connect it in an Nepal electric socket (220V). If you live in an area where voltage fluctuation is common, you must opt for a projector with a wider voltage range. This will ensure your projector works properly, if the voltage fluctuates within that limit.
MOST IMPORTANT
These features notwithstanding, you would want to check service facilities offered by the manufacturing brand - during and post warranty period. Pay more attention to warranty conditions as it covers projection lamp and projector separately.
