High-End Features on Moderately-Priced Projectors

When a screen and projected image are not perpendicular to each other, keystone correction is needed

As a subscriber of this newsletter, you probably already know that video projectors have become more affordable over the past few years. But the recent trend in adding higher-end feature sets, such as optical zoom, automatic keystone correction, and image presets have also made mid-range projectors an improved value. So what are these features and how do they benefit you?

Optical Zoom

If you have ever set up your projector to present and realized that it is not possible to position your projector back far enough for the image size you want, optical zoom is a feature you will appreciate.

Optical zoom allows you to make a larger image from a given distance, without physically moving the projector or sacrificing image quality. As easy to use as a zoom lens on a camera, the optical zoom is usually just the turn of a lens, or a press of a button.

Projectors that have optical zoom have varying degrees of zoom capability. Some can nearly double the size of your image. Optical zoom is listed in the projector specs as a number such as 2.0x, or two times for double the image size from the same distance. This feature may also allow you to use shorter cables, meaning less signal degradation and a lower cable cost.

Keystone correction features

Automatic Digital Keystone Correction

Keystone correction has come in varying forms over the years. Some projectors offer keystone correction by including adjustable legs at the front of the projector, while others are able to square the image digitally through an internal computer.

Automatic correction is an added convenience, as the projector can automatically detect if keystoning is occurring, square the image automatically, saving you time and effort.

Projectors measure keystone correction capability in degrees. Projectors with +/- 40 degrees can correct for greater angles than those with +/- 15.

Image Presets

Sometimes you want the technology you use to just know what you want, without having to do anything. That

Resolution and Your Home Theater

Different projector resolutions provide different results

Anyone shopping for a home theater projector should learn about resolution. It may be the single most important factor to consider when making your final buying decision. So let’s explore a little bit more about the basics of resolution, native high-definition projectors, and getting the best resolution for your money.

Basics of Resolution

Projectors are ‘fixed-resolution displays,’ which means they have a finite number of pixels they can use to display images. A WVGA projector, for example, has a panel inside that is 848 pixels wide by 480 pixels high for a total of 407,040 pixels. Higher resolutions – more pixels – mean better picture quality.

This is not to be confused with video resolution, which is measured in ‘lines’ rather than pixels. NTSC TV signals are made up of 480 lines of resolution, for example. HDTV (high-definition) signals, on the other hand, contain more than 700 lines — hence their superior quality. The projector’s vertical (height) pixel number essentially represents the native video resolution. For example, a 1/4 HD projector (964×544) has approximately 544 lines of vertical resolution.

Available 16:9 resolutions
WVGA 848 x 480 407,040 total pixels
WSVGA (or 1/4 HD) 964 x 544 524,416 total pixels
WXGA-H 1280 x 720 921,600 total pixels
WXGA 1366 x 768 1,049,088 total pixels

Quick Tip: Not sure if widescreen is right for you? Check out our Aspect Ratios tutorial

Scaling Non-Native Images

When a projector receives a signal that differs from its native resolution, a processor inside the projector takes the signal and either up-converts or down-converts (or scales) the image to fit the projector’s native panel. Most projectors can scale signals that are either higher or lower resolution signals. However, anytime a conversion takes place, there is some signal degradation. Your best-looking images will occur when the native resolution of the projector matches the incoming signal line-for-line.

Native High-Definition Projectors

High-definition television signals come in two primary types: 1080i (interlaced) and 720p (progressive). Video projectors are available in either of these two resolutions natively. However, WXGA-H (1280×720) video projectors cost thousands of dollars less than a 1920×1080 native display. The 1920×1080 projector will also have to convert any 720p signals, which means there will still be some image degradation. Both 720p (FOX and ESPN) and 1080i (ABC, CBS) are common on many popular sporting events and cable HD channels.

The Right Resolution for Your Money

So how do you know which resolution is right for your dollar? The best advice is to buy as much resolution as you can afford. More resolution can’t hurt you, and you will likely be happier with your purchase. However, lower-resolution projectors are very tempting given their low price point.

Why Choose a WXGA or WXGA-H Projector?

  • Very affordable ($2,000 or more) when compared to $7,000-$10,000 ’boutique’ projectors.
  • Native 720p resolution for true native HDTV.
  • Images larger than 92″ to 106″ will look cleaner, with less ‘screen door’ effect.
  • Dramatic price increase (near $20,000) for the next level (1920×1080) of resolution.

Why Choose a