Fig. 3. The eye of the small copper Lycaena phlaeas photographed from four dorsal to ventral directions, differing by 30° from each other, with broad-band, white light (halogen lamp) and monochromatic red (670nm) and green (550nm) light. The effective aperture of the objective is approximately 60°. The frontal and ventral parts of the eye contain a mixture of red- and yellow-green-reflecting ommatidia, but dorsally the reflection colours are a mixture of blue and green; red reflection is absent from the dorsal region. The central `hot spot' is due to reflection on the lens surfaces of the microscope objective. 0° is approximately horizontal.