Product Reviews

Current trends dictate that digital projectors must now support XGA resolution (1,024 x 768) natively and offer as many bells and whistles as can be crammed into a compact case. Optoma's EP731 rebels, being an 800 x 600 ultra-portable projector with a relatively low specification that just gets on with the job.

Looking stylish in its aluminium-effect casing, yet surprisingly lightweight at 1.8kg, the EP731 is an uncomplicated projector to say the least. A single quick-release height-adjustable foot is situated at the front-centre of the base, while one of the two rubberised feet at the rear is screw-adjustable to compensate for uneven surfaces. The lens is fixed, not zoom, with a manual focus ring. There's no built-in speaker either.

Mains power plugs into a socket on the left-hand side of the unit, while the data ports are located in a single panel at the back. They're fairly basic ports, but these are the inputs 90 per cent of everyday presenters use. You get a standard VGA-in port for connecting to your notebook along with a passthrough port to hook up an external monitor for convenience. In addition, S-Video and composite video (RCA) ports are available for swift connection of VCRs and camcorders. There's a USB port too, which can be connected to your notebook to allow mouse control and page scrolling from the remote handset provided.

The remote handset maintains the small, uncomplicated theme, but includes a few handy features in addition to basic menu operations and on-screen mouse emulation. There's a digital zoom, for example, which can withdraw to half-size or enlarge an image by up to 8x. Unusually for an entry-level device, it also features digital keystone correction. To be honest, though, we'd refrain from using it except in dire circumstances, because it fuzzes out the image too much, although it shouldn't cause problems in PowerPoint presentations unless you use tiny text.

In addition, there are buttons on the remote handset to freeze-frame video input and blank the screen. One of the buttons will resynchronise the image if it loses stability, but we never had call to use it. Not so well implemented is the Source Select button, both on the handset and on the main unit itself. Instead of just skipping from one input source to another, pressing the button

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triggers a new search for live data across all the ports. This means you can't toggle back and forth between, say, a motion video feed and your PC display without a delay of several seconds every time, forcing your audience to stare at a blank screen while they wait. There are no dual-frame or Picture-In-Picture options either.

One fun little feature is an aspect ratio toggle, which switches the display from 4:3 mode to 16:9. This is great for emulating wide-screen effects for video feeds, so we can imagine the EP731 being popular for home cinema as well as business presentations. It certainly gives computer gaming a compelling cinematic feel when spread across a wall. A third mode keeps the aspect ratio at 4:3, but allows user-defined colour adjustment set up through the on-screen menus.

The 800 x 600 resolution might be unsophisticated these days, but it does make for a stable image. We've seen DLP projectors costing five times as much suffer from shimmer, while the EP731 seems just about rock-solid. Putting the device through extensive test-card routines reveals its limitations, of course, not least in terms of overall brightness and contrast. It's possible to adjust clock and phase settings via on-screen menus in the conventional manner, although we had no call to use them.

Interestingly, bulb life is rated at 2,000 hours, but the same bulb is used in a number of other manufacturers' devices and rated at 3,000 hours. Optoma's explanation is that it only quotes bulb life to 50 per cent deterioration. It still works out at a reasonable 12p per hour, though.

Bulb-life indicator and heat-warning LEDs are provided on the unit. The top of the case does get very warm, like so many ultra-portable projectors, but the real surprise is how quiet the fan runs. The EP731 is built with plenty of space inside the casing to help with heat dissipation, in turn reducing the need for the fan to be thundering away at full blast. This has the knock-on effect of making the projector a little larger, although it's still small enough to be considered an ultra portable. Only when you switch off the lamp does the fan move into full gear to accelerate the cool-down process - if you interrupt this, beware that the life of the lamp will drastically shorten.

In summary, the EP731 gives you the basics plus a few extras at a cracking price. The trick is knowing its limitations. Demanding multimedia presenters will find it lacking in the variety of inputs and the slow switching between them, while IT trainers may well find the 800 x 600 resolution no longer good enough; the EP731 can emulate higher resolutions but this renders images scratchy and indistinct. However, for general business presentations and home entertainment, it's the best-value projector we've tested (and the lightest), with a standard of image quality that's considerably beyond its modest price tag.