Tuesday, March 11, 2014

Spring Flowers 2014: Crocus flower dead vs alive - 80mm Quartz Fluorite lens for reflected ultraviolet photography

Today about something that caught my attention when I was out in the park shooting in reflected ultraviolet (UV) light, here a Crocus. It is the fact that a dead crocus flower dos not show the same colors in UV as one alive, which usually reflects around 385nm. This is not visible in normal light. Shots were done aside from visible photography in reflected ultraviolet light using my standard Baader-U filter. Lens used was my X80QF f3.2 / 80mm Quartz Fluorite lens. Light source was sun. All shots were done at approx. f8.

[click on image to see a larger one]

Visible light image:  

UV image using Baader-U filter (approx. 320-395nm, effective peak approx. 375nm):  

Diptych of the above:  

This early spring flower shows its very specific UV pattern. Crocus usually is reflecting only in long wave UV around 385nm, visible as a bluish violet and its center (anthers, stamen) is UV dark. Its petals inside the flower are UV reflective, maybe caused by the shiny petal surface. But the dead one appears just grey as the stones around, wheras in visible light it looks like the one alive. Pure coincidence? I don't think so. Why should nature wate energy and attract a bee when there is nothing to gain for both sides? This older quartz fluorite lens is reproducing this quite well and all that gets nicely visible.

P.S.: a very alive spring Crocus (C. longiflorus) may be seen HERE

Stay tuned, more will follow on that fascinating subject...