Viewsonic Professional PT813

The current spate of new monitors hitting the market shows no sign of abating, and Viewsonic has entered into the spirit of things by launching two 21in displays. The model reviewed here is the more expensive of the pair and is based on a Mitsubishi Diamondtron screen, rather than the FST-type screen used in the cheaper P810 model. Both offer similar features and controls, although the FST version has a lower maximum vertical refresh rate of 76Hz at 1,600 x 1,200, as opposed to the PT813's 85Hz.

The PT813 weighs 33.6kg, which is hefty but not excessive for a 21-incher, and the cabinet is a relatively compact 520mm deep. Despite its weight, the tilt/swivel stand works well, articulating fairly freely in both planes, but providing firm support for the cabinet once it's been positioned. As you'd expect with a monitor of this class, it has both 15-pin VGA (D-SUB) and five-way BNC signal inputs, but you only get a normal VGA cable in the box.

The physical controls are minimal: just a power stud and four buttons, with most of the action being confined to a clear, but fully-featured on-screen display. There are comprehensive geometry adjustments with the flexibility and range to cope with any normal distortion, plus colour temperature selection, convergence and focus tuning. There are three pre-set colour temperatures and a RGB-adjustable custom channel, and both the convergence and purity controls operate vertically as well as horizontally.

In terms of specifications, the Diamondtron tube puts up a good show. It can handle vertical refresh rates of 132Hz at 1,024 x 768 and 100Hz at 1,280 x 1,024, which should be enough to ensure the appearance of stability for almost everybody. It even manages the VESA-recommended 85Hz vertical at 1,600 x 1,200, but things aren't quite as good as they seem on paper.

Everything up to and including 1,152 x 864 looks great, with crisp enough focus to distinguish individual blocks of pixels in the text of menus and other screen objects. Once you step up to 1,280 x 1,024 however, the sharpness of focus starts to go and small text becomes slightly soft-edged.

This wasn't a misconvergence problem, and no amount of fiddling about with the focus controls could alleviate it, so it has to be down to the fundamentals of the tube itself. Jacking the resolution right up to 1,600 x 1,200 didn't actually worsen the effect, but everything was so small by then that it was difficult to read the screen. Consequently, I wouldn't recommend this monitor for use at that resolution, and I had my reservations about its suitability for long-term use at 1,280 x 1,024.

Author: Dominic Bucknall