George Cole reviews the latest in conventional and portable overhead projectors. Someone once described an overhead projector as a "biscuit tin with a lamp inside". There's a bit more to them, of course, but the description aptly describes the simplicity of the technology.
OHPs are generally robust, reliable and easy to set up and use. It all helps to explain why sales are up and many new models are being launched. Last year, more than 35,000 OHPs were sold in Britain, with the bulk of them going into schools. There are over 100 different models on the market.
Schools Vision's new Educator Range consists of two models, the Ed100 and the twin-lamp version, Ed200 (Pounds 139). Both are basic classroom models, with little in the way of frills. The Ed200, which we looked at, is easy to assemble; simply unlock the arm or column, pull it up, plug in the mains cord and you're more or less ready to go.
The build quality inspires confidence and the Ed200 seems well able to cope with the knocks and bumps of everyday classroom life. The 250-watt lamp is bright and anyone who has ever had an OHP lamp blow during a lesson will welcome the provision of an extra bulb. A small lever on the front of the Ed200 is used to select each lamp. If you're looking for a simple, no-fuss OHP for general classroom use, then the Ed200 should fit the bill.
The answer to schools which need to move their OHPs around could be a portable model. Until recently, the high price and fragile construction made portables unsuitable for most classrooms. But prices have fallen and today's portables are more robust. Even so, it's worth bearing in mind that portables are not suitable for multiple overlays, acetate rolls or LCD panels (for displaying data from a computer or video source).
The Vega Overlight E2 is also marketed by Drake as the Drake Portable Twinlight. Its price is Pounds 300-Pounds 379 (ex VAT), depending on where it's bought. The version we reviewed uses an electronic power transformer which is lighter than a conventional transformer. As a result, the E2Twinlight weighs around 5kg, compared with 7.5kg for the conventional version. It also costs around Pounds 50 more.
The E2Twinlight folds down to a compact size and comes with a handy carry case. The carrying handle is actually part of the OHP's base. This model feels quite comfortable to carry around one-handed, and it's also easy to set up and use.
Everything is set out simply and there's a neat little focusing ring for sharpening up your images. You can display images up to around eight feet across, which is fine for a classroom audience, but not for a hall. The E2Twinlight has two 250 watt lamps, and these are easily accessible for changing.
This is a nice model to use and because it sits low on a desk or table, you are not obscured from your audience. The downside is that it's easier for the OHP's mirror to get marked or scratched by objects placed on top of it. But all in all, a good OHP.
Elite's Colourmatrix 575 is a classic case of nice machine, shame about the price. At Pounds 6,495, it's hardly an everyday purchase, but then this is no ordinary OHP. The Colourmatrix is a combined OHP and high-quality LCD panel. It is a compact machine and weighs less than 10kg. It has a thin-film-transistor (TFT) LCD panel and uses a powerful 575-watt metal halide lamp. The lamp is so bright that you can use the Colourmatrix in daylight. There are controls for adjusting colour, contrast and brightness, and there's even a function menu which saves your personal settings. There's also a remote control handset.
You can link the Colourmatrix to a notebook or desktop computer, and a special lead lets you display information on a desktop computer and a screen at the same time. The image quality is excellent, even in bright daylight, and there's also an inverse facility (this reverses colours) which helps to make some displays easier to read. You can also use the Colourmatrix as a conventional OHP, although the display size is quite small. It would also be useful if the machine had a wide-angle lens for work with large groups.
The Colourmatrix is expensive, but it is a sign of where OHP technology is going. Not so long ago, portable OHPs and LCD panels were well out of the reach of schools, but this is no longer the case. The same thing will happen with excellent models like this one.
Schools Vision, The Saville Group, Millfield Lane, York YO2 6PQ
Vega Overlight E2
CTI, 56 Copthorne Road, Leatherhead, Surrey KT22 7EE
Drake Portable Twinlight
Drake Audio Visual, 89 St Fagans Road, Fairwater, Cardiff CF5 3AE
Elite Colourmatrix 575
Elite Optics, Unit 12,Llantrisant Business Park, Llantrisant, Mid Glamorgan, CF7