(7 Oct 2016) This is the same mantid fly as the the one in last week’s photo, but now focused on the eye. My goal was to show the facets that make up the eye. Insects have compound eyes, consisting of facets. Each facet perceives light from a certain angle. The compound eyes of nocturnal insects are very different from diurnal insects, because they provide a less detailed picture but are up to 1,000 more sensitive. It is like a camera: higher ISO means higher sensitivity but lower detail.
f/10, 0.4 seconds, ISO 100. 60 mm macro lens with an extension tube of 20 mm. This setting allowed me to get very close to the fly and focus entirely on the eye. Because of the very close distance the depth of field is extremely slim, but by using a smaller opening (f/10) it is increased again. Because the creature did not move at all, an exposure of 0.4 seconds worked.
The fascination is with the facets that make up the eye. The eye is most certainly not bigger than 1mm across, making each facet about 1/40 of a mm.