BIOS: Technology Means Business

Acer's top-of-the-range ultra-portable projector, the PD321, is one of the smallest projectors we've ever tested. Its highly-portable form factor and robust silver magnesium enclosure are perfect requisites for business travellers, but its diminutive size comes at a price of bright, crisp and colourful images. The PD321 is a breeze to setup and control, and you'll hardly notice it as you travel between meetings, but you'll soon start to find faults with its performance if image quality is remotely important to your organisation.

Pros: Diminutive size; easy to setup and use; relatively bright
Cons: Poor image quality; limited controls; gets really hot

The PD321's small form factor is achieved primarily thanks to its use of DLP (Digital Light Processor) rather than LCD (Liquid Crystal Display) technology. LCD and DLP each have unique advantages over the other, and neither one is perfect, so it's important to understand the differences before making a purchasing decision. Developed by Texas Instruments, DLP projectors work differently than their LCD counterparts by instead of having glass panels through which light is passed, the DLP chip (Digital Micromirror Device) is a reflective surface made up of thousands of tiny mirrors. Each mirror represents a single pixel.

LCD projectors tend to produce slightly sharper images than DLP, which is more evident in data applications than when playing back video. LCD projectors are also more light efficient and produce significantly higher ANSI lumen outputs than DLPs with the same wattage lamp. However, DLP projectors can produce smoother, higher contrast video with lack of pixelation (in theory), which is why they've been well received in the home theatre world. DLP projectors - the newer of the two technologies - have also come on greatly in terms of colour, contrast, brightness, and image stability.

The PD321 measures just 198x148x57mm and weighs a slight 1kg. It offers a native resolution of 1024x768 pixels (1280x1024 compressed), brightness of 1,100 ANSI lumens from a 120-Watt lamp (2000 hours claimed life), and a contrast ratio of 2000:1, specifications which are impressive for an ultra-portable projector. The unit is compatible with NTSC, PAL, SECAM, HDTV (720p, 1080i), EDTV (480p) and SDTV (480i) video formats, and it also supports both 4:3 and 16:9 aspect ratios, so it's a fairly accommodating solution for watching video at home after a day in the office. We were disappointed that there is no DVI input option though, as well as the lack of any wired or wireless networking options.

A respectable throw distance of 0.6-12 metres also makes the PD321 suitable for achieving an image size of 0.5-6.79 metres (diagonal size) in smaller rooms, opposed to some other DLP projectors that require a minimum throw distance of around 5 metres to get a half-decent image size. The projector also scores highly in other areas, such as its relatively low operating volume of 34dB, digital keystone correction controls, manual zoom lens and Picture-in-Picture support, which allows you to display video in a small window while delivering a presentation.

There's also frequency, tracking and positioning controls (horizontal and vertical), but only vertical keystone correction, so you have to take a little more care to position the projector at the correct height from the projection wall. There are no pan controls either, but you do get a digital zoom function that allows you to enlarge and scroll around an image. We were also surprised at the lack of switchable colour spaces and temperatures.

Connectivity options are limited, comprising 15-pin VGA, S-video and composite video ports. There's no audio input or output options so you'll have to drive audio from your laptop or external A/V source. Acer's Web site incorrectly states that the PD321 offers a USB port for an optional remote mouse, but there's no USB port provided. Bundled accessories include an AC power cord, 15-pin VGA cable (1.8 metres), composite/HDTV video cable, S-Video cable, credit card-type remote control (lacks mouse control and a laser pointer), multi-language user's guide (supplied on CD-ROM), lens cap (hanging) and soft black carry case.

In out tests the PD321 performed moderately when projecting general office applications, digital photos, and geometric patterns from a laptop PC as well as from other video sources (a DVD player, Xbox, and DV camcorder). The unit's rated brightness level of 1100 ANSI lumens confidently displayed black text on a white background, but text-filled screens appeared jaggy at both its optimum resolution of 1024x768 and compressed resolution of 1280x1024 pixels. Graphics, images and movies were even more disappointing, with poor contrast and brightness levels, terrible greyscale levels, and below-par geometry.

Colours were also washed out and lacked any real conviction. In real-world terms, what this means is that fine details in light and shadowed areas, such as in complex graphics and movies, will not be evident. You'll also find that light colours won't appear, such as those used as background colours in presentations, making the projector unsuitable if you work with schematics, maps and other detailed documents.

Links:
Acer PD321 Web site

About our tests:
To test imaging devices BIOS uses DisplayMate Technologies' DisplayMate, a software utility for adjusting, setting up, calibrating, tuning, testing, evaluating and improving image and picture quality on displays. It's designed to help us achieve the highest possible image and picture quality on any type of computer monitor, projector, TV or HDTV, with support for analogue and digital CRT, LCD, DLP, LCoS and plasma technologies. BIOS uses the software to check every aspect of a display's performance, including sharpness and contrast, colour and greyscale accuracy, as well as screen geometry. Where possible, we always use a digital connection for image quality purposes.