Zinnia, focus-stacked

Zinnia elegans

Zinnia · Brooklyn Botanic Garden · 19 August 2026

A zinnia in the August border, built from a stack of frames refocused through the flower and merged afterward, rather than one exposure at a small aperture - the only way to get the near-side ray florets and the disc florets at the centre both fully sharp at this magnification without diffraction softening the whole image.

The centre is a ring of disc florets opening in sequence from the outside in: the ones already open show yellow anthers, while the dark red ones nearer the middle haven't reached that stage yet. What reads as a single ring of "petals" around the edge is the flower's ray florets, each one a complete, if sterile, flower in its own right. A zinnia head is a composite of dozens of flowers, in the same family as daisies and sunflowers, and the garden ones are all bred from a handful of Mexican species.