Normally used telescope is the Hopkins Forward Oblique Telescope 30°, diameter 10mm length 33cm, and is autoclavable. At the distal end is a front lens complex (inverting real-image lens system, IRILS) which creates an inverted and real image of the subject. A number of IRILS transport the image to the eyepiece containing a magnifying lens. In the Hopkins rod-lens system light is transmitted through glass columns and refracted through intervening air lenses. The 30 forward oblique permits far greater latitude for viewing underlying areas under difficult anatomical conditions.
The Sony Trinitron Colour Video monitor can display PAL, SECAAM, NTSC 3.58 and NT SC 4.43 signals. The appropriate colour system is selected automatically. The aperture, brightness, chroma, phase contrast and volume buttons are controlled by light touch buttons. These settings are retained in memory even when the monitor is switched off. The monitor operates on 220-240 Volts AC. The automatic beam current feedback circuit compensates for beam distortion and always reproduces the same white display on the screen, the super fine pitch Trinitron picture tube giving a high resolution picture of more than 600 lines.