A projector is a device that integrates a light source, optics system, electronics and display(s) for the purpose of projecting an image from a computer or video device onto a wall or screen for large image viewing. There are hundreds of products available in the market and they are differentiated by their resolution, performance and features. These devices can be attached to a computer or video device just as you would connect a traditional monitor.



The term "big screen" is used to indicate a TV size larger than 40 inches in diagonal measurement. Until recently these are usually rear-projection screens, although we are seeing more and more flat-panel displays at competitive prices.

The appeal of Rear-Projection TV (RPTV)

There certainly is a great deal of consumer appeal for RPTVs these days. And it's easy to understand. Part of it is due to the simplicity of the product. After all, what could be easier than getting a bigger TV? If you want a larger image with no muss and fuss, it can be purchased from any local big-screen retailer and delivered within a day or two.

Another the appeal of RPTVs is the impression created by big-screen retailers that RPTVs are cheaper than front projection systems.

Clearly there is a market for both types of home theater solutions. From a practical perspective your room size has a lot to do with determining which approach is best for you. If you don't have a large viewing room, a 40" to 60" diagonal TV will probably be plenty. In this case, the rear-projection solution is more practical assuming you can fit the box into the space.

But if you want the large screen cinema experience and your room size will allow it, front projection is the way to go. Front projectors are made to produce screen images in the range of 70" to 120" diagonal or more. Once people realize they can get a picture up to four times the size for the same money as a good RPTV, it opens up a whole new world of entertainment possibilities.

How good is the Rear-Projection TV

As noted above, the advantages of RPTVs are obvious. There is a wide array of products in different sizes and price ranges. There are usually several local showrooms in most areas. And they are simple to buy and install.

However, RPTVs have several limitations that front-projection systems do not. Among them are limited screen size, poor viewing angles, excessive reflections, poor aspect ratio management, and loss of floor space.

Screen size. An obvious difference, but still worth thinking about for a moment. A 100" diagonal front projection screen is four times the surface area of a 50" RPTV. If you want to put real "theater" in your home theater, the projector and movie screen approach delivers it. RPTVs are just big televisions.

Digital Projectors

A digital projector is an electro-optical machine which converts image data from a computer or video source to an image which is then displayed on a distant wall or screen using a lens system. A typical resolution for a portable projector will be the SVGA standard (800×600 pixels), with more expensive devices supporting XGA (1024×768 pixels). The cost of a device is not only determined by its resolution, but also by its brightness. For use in large conference rooms the brightness should be between 1,000 and 4,000 ANSI lumens.

There are four competing digital projection technologies: high intensity CRT, LCD projectors using LCD light gates, Texas Instruments' DLP technology and LCOS or liquid crystal on silicon. In 2004 and 2005, LCD front projection has been enjoying a come-back because of the addition of the dynamic iris which has improved contrast up to the levels of DLP.

There is a genuine market for both RPTVs and projectors for home theater. RPTVs are simple, but they have limitations in screen size and performance. Projectors and screens require some installation work, but once it is done you end up with a more dramatic theater experience.

The bottom line is this: if you are looking at digital RPTVs and your viewing room can accommodate a 90" or 100" screen, don't overlook the possibility of a projector and screen instead. If you can afford a digital RPTV, you can afford a projector. And dollar for dollar the projector will often deliver the maximum "wow" factor for the money invested.