Invisible Oceans Founder's Collection: Invisible Oceans #80: Pleurosigma I

Pleurosigma Diatoms, one of many thousands of species of marine single-celled micro-plants, that make up the 'grass of the seas'. The spectral colours of this species are structural, not pigment colours, and show well under dark field illumination, as first practiced by Victorian microscopists more than 150 years ago. Very fine striations in the diatom test split the incoming light into rainbow colours, by refraction. These fine striations were regularly used by those early microscope designers and optical engineers as test grids with which to assess the fidelity of their objective lens optics.

Image Quest Studio (1976)

Nikon F2 | Custom Optics | Kodachrome 64