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Projector Features Guide
There's such a wide choice of projectors available, we thought you might need some help working out which is best for you. So here's a guide to the features you should look out for.
Brightness
Resolution
Contrast Ratio
Weight
Data and Video Inputs
Audio Support (Speakers)
Keystone Correction
Lens Shift
Document Camera
Lamp hours (half life)
LCD or DLP?
Price!
Brightness
Brightness is becoming less important as projectors get more advanced.
It's
measured in 'ANSI lumens'. Most projectors released in the last year are around 1500 lumens or above, which is more than adequate for the average
board room seating about 20 people. Brightness is much less important for home cinema as there is an overriding assumption that the projector will be used in a darkened room. However, if there is a lot of ambient
light and you don't want to have to draw the curtains (or if you have a larger audience), you may opt to go for something between 2000 and 3000 lumens. However, expect to pay a bit more
for this luxury!
We have a detailed Projector Brightness Guide and an easy to use Projector Brightness Calculator
The resolution is the accuracy of the image that the projector casts. Most projectors fall into two categories - SVGA (800 x 600 pixels) or XGA (1024 x 768 pixels). Similarly, most computers output a signal which is either SVGA or XGA.
(Home cinema users - please note the majority of dedicated home cinema projectors project a native 16:9 (widescreen) image and fall into one of three resolution categories - WVGA (854 x 480 pixels), WSVGA (1024 x 576 pixels) or WXGA (1280 x 720 pixels). The 'W' stands for 'Wide'.
If you use a PC, you can check which signal you're using. Go to Control Panel and select 'Display', then click the Settings tab. Next to 'Screen Area' you'll see a slider which shows what resolution you're using. If it's 800x600, you use SVGA. If it's 1024x768, you use XGA. You can move this slider and press 'OK' to see the difference between the resolutions.
If you use a Mac, you can check which signal you are using by going to the 'Monitors' or 'Monitors and Sound' control pannel (depending on which Mac OS version you are using).
Most projectors sold today are XGA. This is because most computers sold today are moving to XGA resolution as standard. You can project an SVGA output
signal with an XGA projector without significant loss of quality. However, projecting an XGA signal with an SVGA projector can make your presentation look unsightly.
See our feature about projector resolution for further information on this topic.
If you're concerned about picture quality, don't just look at brightness. Contrast is just as important.
In short, it's a measure of how well the projector can block out light from the lamp, ie. how black is the black? This is especially important for home
cinema applications.
An average contrast ratio is about 400:1 for LCD projectors, whilst some DLP projectors have contrast ratio of 4000:1.
See our features on LCD VS DLP for further information on the difference between the two display types.
Are you taking your projector on the road or leaving it in the board room? If you are on the move, you'll appreciate having a projector that's as portable as you can afford. Thankfully, today's projectors are smaller than ever, with the lightest at around 0.9kgs and easy to carry over the shoulder. However, the desktop models still have more features and represent better value if the projector is going to stay in one place.
You may want to project from a Satellite/Cable box, DVD player of games console as well as a computer, or have all the sources connected and interchange between them. If this is the case, check how many data and video inputs the projector has.
If you want to project only video images or set up your own home cinema, have a look at our Home Cinema catagory. Here you will find dedicated home cinema projectors, the majority of which project in native 16:9 (widescreen) aspect ratio.
See our cables and connections guide for more information on the different types of cables available.
If you're likely to be projecting multimedia with sound, you can either connect your PC or video source to an amplifier, or if this is too much bother you can use the internal speakers (N.B. note an option on all makes and models). 1 watt mono is about standard for most projectors, as they are primarily display devices. This is enough for a room of 20 or 30 people if the only audio is speech. If you want something a bit more impactful, either look for a projector with a 2.5 - 3 watt speaker, or consider the amplifier option.
'Keystoning' is the name given to the effect on the projected image when the projector sits below or above the centre of the screen. Keystone correction counteracts this effect by digitally compressing the image at the bottom or top, resulting in a squarer, more professional image.
Lens shift is generally a feature of high-end projectors or specialist home cinema models. Lens shift has a simular effect effect to 'Keystone correction' except that the effect is achieved by physically adjusting the angle of the projectors lens to square up the image. This is a better method of producing a square image, rather than using keystone correction as the correction with lens shift is acheived optically (rather than digitally) resulting in no loss of quality
Lens shift can also be useful for fine-tuning the position of the projected image on your screen.
A few projectors, mostly in the Toshiba range, have inbuilt digital cameras that output images directly into the projector. This is useful if you have documents that you want to show your audience, but don't have time to scan them in and add them to your presentation.
A standard lamp lasts for about 2000 hours of projecting. That's a lot of presentations, and with lamps sold at £150 and £:500, it works out at betweeb 8p and 25p per hour of use. Projectors with higher lamp half lives are less likely to cause you a problem in the middle of a presentation when the projector gets older and used more, and generally represent better value per hour of use. However, with all projectors a sharp knock can put the lamp out of action no matter how old it is. Environmental factors can also effect lamp life so it's prudent to have a spare on hand.
Until a few years ago projectors were mostly based on LCD technology, where the light from the lamp was filtered through red, blue and yellow LCD panels to produce a full colour image. Having three panels means that the projector casing needs to accommodate more room for the electronics, making the projector larger.
Then Texas Instruments developed DLP technology. DLP converts light straight into a full colour image, allowing manufacturers to make much smaller projectors. The downside is that the accuracy of the colours produced is not as accurate as many LCD projectors, so greens can look quite close to yellows, etc. If colour accuracy is really important to you, we suggest going for a slightly bigger LCD
projector. More on LCD vs DLP >>
Obviously you'd prefer to get your projector as cheaply as possible! Generally XGA adds about 30 to 40 per cent to the price of a projector, while brightness and portability are the other major factors. Weigh up the features you need before buying to get the best value!
Still confused? Then why not just give us a call. We'll ask you a little about what you want to do with your projector, and recommend exactly the right model for you.