Document cameras are an excellent means of displaying detailed experiments, teacher demonstrations or presentations to a whole class at once, which would otherwise be impossible due to the size of the subject matter, as in the case of microscopy.

Although most visualisers are supplied with a microscope adapter, it is not just a bit of kit for the science lesson - far from it. It is perfect to use with a data projector or any large video display device. Most products in this particular genre have come from the videoAV end of the market, and only recently have models appeared that connect comfortably with computers.

So what are the classroom applications of these devices?

The most popular usage is in microscopy. By linking your microscope to a computer it is possible to show the whole class the microscopic image.

Science teachers can also use them with a projector and whiteboard to enable the whole class to see the detail of demonstrations, such as dissections or chemical reactions.

Design and technology departments, too, can use them in a similar way to enable whole classes to see the detail of a demonstration without the old “crowding round the front bench” problems. Techniques which would benefit from this include: soldering or how to populate a PCB; cutting and joining techniques in resistant materials and textiles; and sketching and rendering techniques in graphics. You can also show book pages, maps and small artefacts to a whole class. The possibilities are endless.

For primaries, a document camera would be invaluable for showing minibeasts or plant samples to the whole class. And for any subject that requires looking into awkward places - vehicle mechanics, for example - it is are a fantastic asset. Furthermore, for teachers of visually impaired children, cameras can be placed close to a page so that an enlarged image can be displayed on screen.

Not all cameras work with computers. AVerMedia’s AVerVision 110 (pound;429) and Economatics’ Video Flex (pound;549) both work only with TVs, data projectors or video displays. Both have goose neck cameras which can be bent into the tightest of angles and both have excellent display properties. They come with microscope adapters and as an option on the AVerVision 110 there is a light box and removable light and ’ Demarcating Module. The AVerVison 110 can be particularly recommended. However, Economatics Education offers what must represent the best all-round solution for schools: the Vision Viewer (pound;214).

The goose-necked Vision Viewer offers a cost-effective solution to image capture and whole-class presentation. The camera has a rubber knurled ring for focusing from 8mm to infinity making it a general-purpose classroom digi-cam. The 1.2m integral USB cable is sufficient to give plenty of room for connection to the computer. It connects directly to your computer for full-screen imaging at 640 x 480 resolution and can operate in low-level lighting conditions, although it does not perform well under these conditions. It too comes with a microscope adapter.

The Kenavision Camera software includes features like time-lapse to further enhance the camera’s capabilities. You can capture still images and record movies for use within PowerPoint presentations, etc or broadcast movies across the school network or broadcast live images over the internet.

Overall, Vision Viewer performs very well and is thoroughly recommended.

Promethean ACTIVprimary Price: pound;99.00 (single user) Promethean Limited Tel: 0870 2413194 www.promethean.co.uk

Fitness for purpose **** Ease of use **** Design **** Quality **** Value for money ****

Hitachi Cambridge Board Prices: pound;1,202 (60-inch board) pound;,1382 (70-inch board) Hitachi Software Tel: 020 8902 1286 www.hitachi-software.co.uk

Fitness for purpose **** Ease of use **** Design **** Quality ***** Value for money ****

Vision Viewer Economatics (Education) Ltd Tel: 0114 2813311 www.economatics.co.ukeducation

Fitness for purpose **** Ease of use **** Features *** Quality **** Value for money ***** AVerVision 110 AVerMedia Tel: 01908 218800 Fax: 01908 218818 www.averm.co.uk

Fitness for purpose **** Ease of use **** Features **** Quality **** Value for money ****