Home Theatre Projector Buyer's Guide

Projectors used to be found exclusively in movie theatres and film producer homes. But those days are long gone! Today, improvements in projector technology and lower prices are allowing movie buffs to create the movie theatre experience right at home. Thanks to a number of competing technologies, the prices of projectors have come down to a point that makes them affordable with even the most modest budget.

Types

Modern home theatre projectors are based on one of three technologies: LCD, DLP or LCoS. Older CRT-based projectors also exist but are no longer in production.

LCD projectors have been around for years and are currently the most affordable option. Two types of LCD projectors exist: models which use a single LCD to create the picture and models which use a combination of three LCDs. Projectors that use three LCDs generally produce truer-to-life colour saturation, smoother transitions from light to dark and colour to colour, and offer higher contrast images.

DLP projectors are capable of producing incredibly rich colours and very high contrast ratios, in many cases surpassing the picture quality of LCD projectors. DLP projectors are usually more expensive than comparable LCD models, although their prices continue to come down. As with LCD projectors, high-end DLP projectors use three DLP chips to produce their picture. Three-chip DLP projectors can resolve even finer gradations of shade and colour.

LCoS, the most recent addition to projection technology, is a reflective technology similar to DLP. Instead of tiny individual mirrors, it uses liquid crystals to generate the picture. Currently only two companies produce LCoS-based projectors: Sony which calls their version SXRD and JVC which calls their version D-ILA. In addition to this, Meridian Audio uses D-ILA technology in their projectors. As with LCD and DLP technologies, one and three panel implementations of LCoS exist. LCoS projectors are capable of producing some of the best projection pictures available today but are also currently the most expensive solution.

Contrast Ratio and Brightness

Contrast, measured as a ratio, is the difference between the lightest and the darkest portion of an image. This is arguably the most important specification of a home theatre projector. A projector with a high contrast ratio will generally produce more subtle colour changes, better saturated colours, increased shadow detail and a picture that appears more three dimensional. Entry-level projectors typically offer a contrast ratio of 2000:1 or less, mid-range models vary between 4000:1 and 7000:1 and high-end models offer 10,000:1 or more. Manufacturers usually indicate the contrast as a ratio between the whitest white and the blackest black that a projector can display (also referred to as full-on/full-off ratio). An ANSI contrast ratio is a more accurate measure of the contrast although manufacturers rarely list it. It is a measure of the relative brightness when displaying a white/black checkerboard pattern. Nowadays, many manufacturers also list a dynamic contrast ratio that can reach upwards of 30,000:1. However this is not a real world contrast. It is achieved through video analysis and an automatic (or dynamic) iris. An automatic iris is a device that sits between the lamp and the lens. The projector dynamically evaluates the brightness of the picture being displayed and automatically opens or closes the iris to allow more or less light output. The performance of an automatic iris varies substantially between projector models. Contrast ratio, ANSI contrast and dynamic contrast are not related and cannot be compared with each other. For best results, purchase a projector with the greatest contrast ratio you can afford.

All projector manufacturers also provide a brightness specification measured in ANSI lumens; the higher the number, the brighter the projector picture. This specification is not nearly as important as the contrast ratio because ideally a projector should be used in a completely dark room. A basement home theatre doesn't require as much projector brightness as a living room home theatre with light from windows or light fixtures. A bright projector is not necessarily better for the home theatre. The trick is to select a projector that will display a respectable contrast but won't be too bright and fatiguing to your eyes. Most dedicated home theatre projectors have a brightness of under 1500 lumens. You should also know that brightness is not measured equally by all manufacturers. Some projector manufacturers base lumen values on data output, not video. A knowledgeable salesperson at a reputable store will steer you towards the best brightness for your lighting condition and your budget.

Aspect Ratio and Resolution

Since all movies on DVD and Blu-ray are produced in the widescreen format, all dedicated home theatre projectors have the 16:9 widescreen aspect ratio. Of course, a 16:9 projector can also display a 4:3 picture with black bars on the sides.

Resolution is the number of pixels from side to side and top to bottom of your image. Each pixel is simply a dot of colour on the screen. Most home theatre projectors on the market today offer a high definition picture with a native resolution of 1080p (1920 by 1080 pixels) or 720p (1280 by 720 pixels). As you might expect, the higher the resolution the more the projector costs. If your budget allows for a 1080p model, this is definitely the way to go. The advantages of 1080p (over 720p) are clearly noticeable on a screen that's 50 inches or larger. A 1080p source, such as a Blu-ray disc player or a video gaming system, can produce an incredibly sharp and detailed picture, well worth the extra investment.

Uniformity

Uniformity is expressed as a percentage of brightness throughout the entire projected image. Certain models are incapable of projecting peak lumens out to screen corners. A projector that puts out equal amounts of brightness from the center to the corners of the image has a higher uniformity percentage. The result is more even distribution of light throughout the entire image. Greater than 85 per cent uniformity provides a relatively consistent image.

Fan Noise

Every projector has at least one cooling fan built-in. If the projector is relatively close to the seating in your home theatre, which it is in most cases, the fan noise can be very distracting and take away from the movie watching experience. Entry-level projectors generally produce 35 dB or more of noise. Mid-range models keep the noise down to 30 dB or less. Some projectors offer a "wisper quiet" mode which can reduce the noise to under 20 dB. This is usually achieved by decreasing the overall brightness of the picture. We recommend buying the quietest projector that you can afford.

Throw Ratio

The throw ratio has to be considered to determine if a given projector will produce a desired image size in your room. A projector's throw ratio is defined as the distance (D) from the lens to the screen divided by the horizontal width (W) of the projected image. Since projectors have zoom lenses, the distance in the throw ratio is expressed as a range. For example, let's take a projector with a throw ratio of 2.0 - 2.4:1. To achieve a 6 foot wide image, the projector will have to be placed at a distance of 12 feet (6*2) to 14.4 feet (6*2.4) away from the screen.

Lamp Life

Projectors typically have a lamp life of between 1000-2000 hours. Newer models claim a 4000 hour lamp life or longer. This spec is actually the lamp's 'half-life.' The half-life is the point where the lamp is half as bright as it was new. The lamp will still work at its half-life, but it will continue to gradually lose brightness. Longer lamp life means less expense in maintaining your projector.

If your projector is replacing your television, factor lamp replacement cost into your purchase price. Replacement lamps run approximately from $300 to $450.

If your projector will be used primarily for watching movies and special events, lamp life will not be quite as important. But you may still want to factor the cost of a replacement lamp into your purchase.

Video Inputs

Every projector offers a number of different quality video inputs. From best to worst these inputs include: HDMI, component, S-video and composite video. Many models also offer a VGA input for connecting a computer. You may also find a DVI connection in some older models. This connection has been completely replaced by HDMI. A projector with an HDMI input will allow you to achieve the best quality picture with the highest (1080p) resolution. The latest models are capable of displaying 24 fps signals via HDMI. Most Blu-ray high definition discs have the 24 fps rate and produce a smoother, film-like picture when paired with a 24 fps projector. A number of different versions of the HDMI connection exist. To learn more about the different version please read our "Making the HDMI Connection" feature at www.canadahifi.com.

How many video inputs should a projector have? In practice, a single HDMI input is enough for most home theatres. That's because all the video sources are usually plugged into an A/V receiver and then sent by a single HDMI cable to projector. The only exception is if you also want to connect a computer to the projector. In this case, the projector will need to have a VGA input since A/V receivers do not offer this type of input.

Click here to read our guide on Connecting your Home Theater with the Proper Cables

Setup Adjustments

Entry-level projectors usually have manual zoom and focus adjustments. More expensive models offer electronic zoom and focus, accessible via the remote control. Some projectors also come with a lens shift feature which allows the lens to move horizontally or vertically within the projector housing. This is a very handy feature that will allow much greater leeway in the placement of a projector in your room. Again, lens shift comes available in manual or electronic versions. Some projectors offer keystone correction in place of a lens shift. This is essentially a digital way of achieving a lens shift, by means of digitally altering the image before it reaches the projection lens. However, since keystone correction usually slightly distorts the image, lens shift is a preferred feature.

Video Processing

A quality video processor will vastly improve the look of 1080i material from HD channels and Blu-ray discs (recorded at 1080i). When a 1080p projector is fed a 1080i signal, the signal has to be properly de-interlaced by the video processor. A quality projector should also properly detect and compensate for 3:2 pulldown in film-based 1080i material. Some projector manufacturers use third-party video processors in their projectors, other manufacturers design their own processors. Video processing between projectors can vary substantially.

Read Reviews

Projectors are not as easy to demo as TVs and hence you are unlikely to be able to play with a projector in the store. Reading reviews of projectors can go a long way to making an informed choice before buying.

Projector Screens

Click here to read our Projector Screen Buyer's Guide.