Viewsonic's mid-level PJ551D is a portable projector that punches above its price point. It's not lightweight, but it performs capably for both office presentations and displaying HD content. Travelling users may get put off by the weight though, and the comparatively low brightness may cause problems in some conditions.

The projector's design isn't particularly innovative — a matte black finish and silver-accented buttons. It's roughly the size of a sheet of A4 paper, so its small stature and colour won't draw attention in a darkened room. At 2.7kg kilograms it's quite heavy, especially when compared to the diminutive Toshiba TDP-P9.

Connectivity isn't the best we've seen. The PJ551D offers users an option of three inputs: VGA D-Sub, S-Video and Composite. While its competitors offer a wider range of choice, these three will suffice given the projector's resolution. We would have liked a DVI input, allowing connections from high-definition players and a wider range of computers.

Setting up the projector is simple. It can be attached to a ceiling and function from the front or rear of a projector screen, which helps if you're in a difficult or cramped location. An adjustable front leg allows for height adjustment and the horizontal angle can be altered by unscrewing one or both of the rear feet to counteract uneven surfaces.

The controls for the PJ551D are well thought out and easy to use. The buttons are easy to press and can be distinguished from each other in a dark room. A slimline remote is also bundled and allows all the projector's functions to be controlled from across the room.

The user interface is well designed; a series of sub-menus hide advanced information and settings. Adjustment options are plentiful, with brightness and contrast settings easily accessible. For users desiring a versatile projector for a wide range of locations and uses, this is a definite advantage.

Native resolution is 1024x768; 800x600 pixel presentations are displayed accurately, with only a small amount of fuzziness visible from the projector's internal up-scaling.

Equally impressive is the projector's ability to scale high-definition content. Played through a BenQ Joybook R45 (PV-04) laptop connected via D-Sub VGA, 720p video files were displayed with only a small amount of fuzziness. The projector isn't a widescreen one by default, so any 16:9 videos must be displayed within the standard 4:3 window — resulting in a comparatively small projection size. 1080i content delivered through the same laptop didn't fare as well. Down-scaling to the Viewsonic projector's native resolution resulted in noticeable jaggedness.

A decent contrast ratio of 2000:1 means that the PJ551D is able to display pictures and videos with a respectable degree of depth. Like most portable projectors, it's not fantastic for viewing photographs and video which have a lot of detail in dark areas, but in most situations it performs well. Quoted brightness is 2200 ANSI lumens in full brightness mode, on par with older models but significantly less than current leaders like LG's DX130, which sports an impressive 3000 lumens. Colour reproduction is quite good for a portable model, with all colours evenly displayed.

We found noise levels very good, especially considering the combination of small size and heavy weight. When changing to the projector's economy mode, the fan was almost inaudible, even when running for long periods.