Moth Wing Scale — Iridescent Lepidoptera Architecture

Description

Butterfly and moth wing iridescence is produced not by pigment but by structural colour — nanostructured ridges on each individual wing scale act as a diffraction grating that reflects specific wavelengths of light through constructive interference. At the magnification required to resolve these structures optically (approximately 20:1), a standard optical macro setup is at its resolution limit, but the structures on the large scales of moon moths and Morpho butterflies are just large enough to resolve in extreme macro photography. This image was made at the resolution limit of optical macro photography using a 5:1 macro lens and 4:1 extension, the scale architecture visible as parallel ridges spaced approximately 200nm apart on the scale surface. The structural colour is visible even at this magnification — different areas of the same scale show different colours as the viewing angle relative to the ridge orientation varies across the field of view.