Philip Harris has produced a range of digital microscopes that are easy to use and offer a relatively inexpensive video microscopy system. Based on Philip Harris's Advanced and College ranges, the microscopes contain an integrated camera which allows a feed to be taken to a computer or, in some models, directly to a TV.
The microscope is supplied with free software that has the familiar look of Windows applications and so is fairly intuitive to use. Connection is straightforward, with the microscopes automatically detected as a "plug and play" device when attached to the computer's USB port.
Focusing and adjustment are the same as on other microscopes, and images can be viewed on the computer screen or by the whole class using a PC projector. The software allows manipulation of captured images, which can be stored for later use or assessment. Addition of labels and highlighted areas will help pupils understand the images, which could be shared and used in other subjets over a school network.
Following a straightforward calibration, measurements of length, regular and irregular areas can be made, with the resultant data displayed in a tabular form for analysis in a spreadsheet application. A time-lapse feature (minimum of one frame per second) will record slowly changing events such as crystal growth, although long timescales would be limited by available disk space and the stability of the microscope. While not tested, the TV output may be used for observations of living materials such as the heartbeat of a daphnia (water flea).
The innovative use of these microscopes will help pupils interpret the images they are viewing, and gather data for use in other subjects or ICT applications.
Technical specifications: camera 640 x 480 pixels; objective lenses: x4 to x40 (standards) x100 available; built-in light source and adjustable condenser; mechanical specimen stage.
PC minimum requirements: 200MHz CPU, 64Mb Ram 200Mb hard disk space, Windows 98 or greater. Windows NT is not currently supported. Driver for Apple Macintosh is available on request. USB port and CD-Rom.
Cliff Porter is a freelance writer on science education