Most projectors are capable of taking inputs from both a PC and video sources, such as a DVD player or TV. However, most are also optimised either for PC use or for home cinema.

One of the most important factors to consider when looking for high image quality is the native resolution of your projector. The most common resolutions for home cinema at present are WVGA, WSVGA and increasingly WXGA. The 'W' stands for Widescreen, which is the format mostly used in home cinema. The higher the resolution the higher the number of pixels are displayed and therefore the sharper the image. Higher resolution also means better compatibility with high definition sources such as HD DVD, Xbox360, PS3 and HD TV.

If your source has a higher resolution than the projector then the image is digitally compressed which will result in lower sharpness and colour accuracy.

Standard 16:9 resolutions are:

Resolution	Width x Height in pixels	Total number of pixels displayed (approx)
WVGA	848 x 480	407,000
WSVGA	964 x 544	524,000
WXGA	1280 x 720	922,000
UWXGA	1920 x 1080	2 million

We recommend a minimum of WXGA (1280x720) as the best choice if you have any HD (high definition) sources. If you require a projector to be used solely with a DVD player which has a native resolution of 480P (ie 480 pixels tall), and do not plan to have any HD sources in the near future, a WVGA will cost you less money and is worth considering.

However in most cases a home cinema projector should last 4 to 5 years before you consider upgrading, so think about any other upgrades you may make in that time in your home cinema set-up.

What you are watching (your source material) will make a big difference in the quality of your image. A low quality signal into your projector will most likely look like a low quality signal when projected, and on a larger screen may be even more noticeable. For best results, you should try and match the native resolution of your source material. A progressive scan DVD player is typically a 480p signal (WVGA), while HDTV signals are 720p (WXGA) or 1080i.

The contrast ratio is the ratio between the white and black parts in an image. The larger the contrast ratio of a projector, the greater the difference between the brightest whites and the darkest blacks a projector can show. A contrast rating of 1000:1 would imply that the black level is 1000 times darker than the white.

You might wonder why black has any brightness at all – this is just because all projectors emit light 'leakage' to some degree. A higher contrast ratio implies that there is less light leakage, which means your image appears less faded.

Current standards are that an LCD home cinema projector will range from 5000:1 up to 10,000:1 where similar performing DLP projectors are rated around half of that of LCD so from 2500:1 to 5000:1

If there is a high level of ambient light or you do not plan to have the lighting controlled with blinds and controlled lighting then you will need a higher lumen projector. For low level ambient light 1000-1200 lumens should be sufficient. In a controlled environment (blackout blinds or heavy lined curtains and controlled lighting not in the direction of the screen) then anything from 800 lumens and upwards will be more than adequate.

Most projectors typically have a lamp life between 2000-4000 hours. This specification is actually referring to the 'half-life' of the lamp at which point the lamp is half a bright as it was when it was new. Longer lamp life normally means lower costs replacing the lamp in your projector.

If you are planning to use your projector to replace your current television, lamp replacement cost should be factored into your purchase as you will have a higher level of usage. Through regular cleaning of the filters you may improve the life of a lamp, as will proper operation by powering the projector down rather than just removing power.

If you purchase a spare lamp with your projector, we’d advise that you run it in your projector for a few hours first and then store it somewhere cool and dark where it won’t get knocked or dropped. Lamp warranties begin from the day of purchase, not from the day of use. If a lamp is faulty, it will generally fail within the first 4 to 10 hours of operation.

To get the best out of your investment use a proper projector screen. This will give you a better image quality in terms of brightness and colour reproduction.

You will probably want to get a 16:9 screen if you’re using it for home cinema or own a current generation games console. You also need to find the ideal screen size. This can be calculated by knowing the throw distance you have available (the distance between the front of the projector and the area you are projecting onto). Using the screen size calculator you can find the screen size that matches your projector and the area available. See our screens page for a full selection of screens and use our screen size calculator for help on screen sizes.

Bear in mind that bigger doesn’t necessarily mean better. If you’ve ever sat in the front row of a cinema and walked out with a stiff neck, you’ll know what we mean.

There's been a long running battle between LCD (liquid crystal display) and DLP (digital light processing) technologies. Both have merits for home cinema. Here's a brief summary.

LCD	DLP
No rainbow effect	Rainbow effect experienced by small proportion of users. Virtually eliminated if the projector features a 4 x speed or greater colour wheel.
Slightly more saturated "truer" colours	Less saturated colours, but improving significantly, especially with the introduction of 8 segment colour wheels.
Contrast ratios up to 10000:1	Contrast ratios up to 5000:1
Small gap between pixels, resulting in slight 'screen door' or 'chicken wire' effect.	Much smaller gap between pixels, resulting in smoother overall image
Small possibility of 'dead' pixels	Dead pixels virtually non-existent

Both LCD and DLP have evolved rapidly over the last five years, and we have now reached a point where the immense gap between the two technologies is relatively narrow.