Further proof that this is a product for the portable presentation is the wide angle lens, which lets you create a wide image from a surprisingly short throw. With a range of 0.7 to 9m, the PJ551 is capable of reproducing an effective image size (measured across the diagonal) from 30-300in. with our test set up providing a 120in diagonal from a throw of only 3.2m. Digital keystone correction can be used to adjust any distortion caused by an upward projection angle, though this results in image artefacts where pixel data is discarded. Rear projection is also supported, though ceiling mounts are not – no surprise from a product that hasn’t been designed for installation use.
As far as image quality is concerned, the PJ551 acquitted itself fairly well, with even screen uniformity, and the kind of colours you’d expect from an LCD product. The lower contrast ratio means that it’s not as good as some projectors at reproducing the full gamut of shades, and it has a tendency to lose very shallow variations, particularly at the very bottom of the grey scale. We also found a small amount of ghosting present on high-contrast scenes, but not so much that it’s noticeable during general use. The typical gamma value of the projector is set to 2.2, though the PJ551 offers a dynamic setting that adjusts itself according to the current signal input – higher for PC connections for clearer text, lower for video to allow more accurate tonal reproduction. As well as helping to maintain the brightness of the image, the microlens layers used by the PJ551’s P-Si LCD panels help to reduce the visible pixel structure for a softer, less ‘digital’ appearance.
Colour reproduction is good, and can be tweaked with red and blue channel variation, contrast and brightness for PC connections, with hue, sharpness and saturation adjustments for video connections. Convergence wasn’t great though, and we found a significant amount of deviation between red and blue pixels at the extreme corners of the display. This results in noticeable colour fringing on objects, and is particularly evident when projecting a standard windows display with text.
Another concern is the noise that the PJ551 makes during use. Even in standby there’s a high-pitched whistle coming from the PSU, while the cooling system is very loud when in operation – a serious consideration when you’re likely to be sitting quite close to it in a meeting room. This can be reduced with the ‘whisper’ mode, but not enough to justify the name. This mode will also reduce the brightness of your projection, as well as the overall power consumption.
Overall, we’d have to say that the ViewSonic PJ551 is a respectable product, if not especially outstanding. If you’re looking for a reasonably-priced portable presentation aid with an acceptable level of image reproduction, this would do the job pretty well – assuming that you can live with the colour convergence problems and the noise it makes.