Fig. 4
From: Unique wing scale photonics of male Rajah Brooke’s birdwing butterflies
Optics and ultrastructure of the blue wing scales. a Epi-illumination light micrograph of an area with variously blue colored scales (area 6 in Fig. 1b). b Reflectance spectra of scales with numbers corresponding to those in panel (a). c Scatterogram (the red circles indicate scattering angles of 5, 30, 60, and 90°. d Scanning electron micrograph of a blue scale, showing high ridges. e Transmission electron micrograph of a blue scale, with an electron-dense core of the ridges. Scale bars: a 100 μm, d, e 1 μm