The Intel digital microscope has proved very popular in schools - especially in those establishments where it arrived as a ‘free’ gift! We reviewed it in our secondary schools’ Bulletin 112 and in our Primary Science & Technology Newsletter 21. We indicated that, although it is a very valuable means of helping young children to capture and manipulate microscope images, it has some optical limitations. It was interesting, therefore, to see an alternative microscope on display at the January 2003 ASE conference in Birmingham. We have now had a chance to find out, first-hand, whether the impressions we gained at the time were correct.

Unlike the ‘Intel’ model, this is a ‘proper’ optical microscope with a matched digital imaging attachment to replace the eyepiece for use with a computer. The instrument can be used free-standing, in which state it actually looks like a microscope rather than a time capsule! A zoom lens allows for direct magnifications between 20 and 100 times, with intermediate stops at 40, 60 and 80 times. However, a disadvantage of the optics used is that it is necessary to refocus (and sometimes recentre) the image whenever the magnification is altered.

As with the ‘Intel’, the microscope can be detached from its stand and used as a roaming magnifier (in this case, with or without the digital camera attached). Unlike the ‘Intel’, however, power for its two sources of illumination (above and below the specimen) comes from three AA batteries (not supplied). This makes it more portable. The digiscope light bulbs are solid state; therefore replacements are unlikely to be needed and the batteries should last a good while. There is no indicator to show when these dimmable lights are ‘on’, so check before putting the microscope away or leaving it for a period!

The mouldings which form the microscope stand and tube are robust and likely to withstand normal classroom use. The base includes a plate with clips to hold slides in position - a very worthwhile feature. This can be replaced by another plate, one side of which is smooth, for examining whole specimens. The other side of this plate has a small well for examining specimens such as small pond animals.

The digiscope comes with various ‘extras’ and, along with the now-usual range of prepared slides, blank slides, Minispector-type magnifiers, tweezers and dropper, there is also a calibration slide. This invaluable accessory enables children to measure the magnification achieved on the computer monitor screen. The magnification is much greater (but scarcely more detailed) than that observed by looking directly through the microscope eyepiece. Instructions for calibrating the magnification are provided in the ‘Quick Start’ booklet. There is also a book giving practical suggestions for those with little experience of microscope work.

For this, the microscope eyepiece is removed and replaced by the digital camera. The camera is not keyed into the microscope tube and so is free to rotate. The image will also rotate, of course.

Attachment to a computer is via a USB connector. Software is provided on a CD-ROM in the usual way. The software supports PC Windows 98, ME, 2000 and XP and also Apple Mac OS 9.x. It allows image capture, measurement, saving and simple manipulation. The appearance of the display is designed to appeal to younger pupils, despite the optical quality of the instrument. However, a full-screen display of live pictures does not appear to be possible. It is necessary to save the image and reopen it using a graphics package to produce a high-quality, full-screen image.

• It is a reasonably well-made, robust microscope that can be used in the conventional manner.
• The microscope tube can be detached from the stand, and used with or without the digital imager.
• The digiscope’s optics are capable of producing satisfactory images even at higher magnifications, making the instrument suitable for KS 2 pupils and as a digital device for use at KS 3.
• Illumination is self contained using white LEDs.
• The instrument has satisfactory arrangements for holding slides and wet specimens steady. Although refocusing and centring are necessary whenever the magnification is changed, this is not difficult since imaging takes place very quickly.
• Once calibrated, it is possible to measure specimens.

• The software has a ‘play’ image that belies the quality of the optics. It could put off some older pupils at KS3 who might benefit from its use.
• It is difficult to obtain a full-screen view of the image - the image must be saved and reopened in a graphics package to do so.
• There are many detachable and desirable parts, so it will be necessary to check that such items as the camera, eyepiece lens and stage do not ‘walk’!
• The camera can rotate on the body - this can be useful, but needs to be borne in mind when discussing images with children.

We feel that the Motic Digiscope 300 is better for science activities than the Intel model; but not quite so useful as an IT resource.

The instrument is available from a number of suppliers. For example:

Philip Harris Education, Cat. no. C0H70322, £110.00

Findel House, Excelsior Road, Ashby Park, Ashby de la Zouch LE65 1NG.

Tel: 0845 120 4520; Fax: 01530 419492;
E-mail: customerservice@philipharris.co.uk; Web site: www.philipharris.co.uk

TTS, Cat. no. SDIGI, £119.95

Nunn Brook Road, Huthwaite, Sutton-in-Ashfield NG17 2HU.

Tel: 0800 318686; Fax: 0800 137525;
E-mail: sales@tts-group.co.uk; Web site: www.tts-shopping.com