Andrea B. Posted July 13, 2013 Share Posted July 13, 2013 Blum, A.G. (2013) Taraxacum officinale F.H.Wiggers (Asteraceae) Dandelion. Flowers photographed in ultraviolet, visible and infrared light. http://www.ultraviol...nale-dandelion/ SET 1Twin Pines, La Plata County, Colorado, USA28 April 2013Wildflower Synonyms:Leontodon taraxacum L.Taraxacum dens-leonis Desf.Taraxacum retroflexum Lindl.Comment:The ubiquitous Dandelion, with its UV-dark center bullseye, is a classic UV photographic test subject. The T. officinale styles are UV-black. Note that on the rays there is no clear demarcation between the UV-dark proximal area and the UV-bright distal tips. Rather, the UV-dark ray area is rather diffuse, but in aggregate with the UV-black styles gives the appearance of a central bullseye. The longer, outer rays have significantly less UV-dark patterning. For an extensive discussion of Taraxacum in North America please see the listed Flora of North America reference. In the Taraxacum genus entry(1), Luc Brouillet writes: I have adopted a broad definition of Taraxacum species for North America, broader at least than what is usually seen in European treatments. For instance, the species most familiar to North Americans were introduced from Europe (T. officinale and T. erythrospermum,...), possibly several times, and represent variable agamic complexes, but this variation appears continuous and multidimensional. There seems to be no utility for the users in describing a multitude of narrowly defined microspecies.However, perhaps future UV studies of Taraxacum might reveal some identifiable differences between the microspecies. Reference:1. Flora of North America Online (2013) Taraxacum vol. 21 pg. 239 FNA. New York & Oxford. http://www.efloras.o...taxon_id=132314 Equipment [Nikon D600-broadband + Nikon 105mm f/4.5 UV-Nikkor] Visible Light [f/8 for 1/1250” @ ISO 200 with Nikon Coolpix A] Visible Light [f/8 for 1/1000” @ ISO 200 with Nikon Coolpix A] Ultraviolet Light [f/11 for 1/125” @ ISO 400 with SB-14 UV-modified Flash and Baader UV-Pass Filter] Link to comment
Andrea B. Posted June 4, 2015 Author Share Posted June 4, 2015 SET 2Middletown, New Jersey, USA18 April 2010Wildflower Comment:A fine field of Taraxacum was blooming on this suburban street corner. Equipment [Nikon D200-broadband + Novoflex 35mm f/3.5 Noflexar] Visible Light [f/11 for 1/1000" @ ISO-800 in Sunlight with Baader UVIR-Block Filter]A nice crop of signage was also growing. Ultraviolet Light [f/11 for 1/4" @ ISO-800 in Sunlight with Baader UV-Pass Filter]This is a stack of two frames for improved depth of field.When seen en masse in UV, the central bullseyes really do appear to be targets. Visible Light [f/8 for 1/250" @ ISO-400 in Sunlight with Baader UVIR-Block Filter] Ultraviolet Light [f/8 for 1/4" @ ISO-800 in Sunlight with Baader UV-Pass Filter]The dandelion stem often reflects false blue in UV light, but I didn't see much of that in this field. However, most of the Taraxacum stems were in the shade of the tall grass. Visible Light [f/11 for 1/125" @ ISO-400 in Sunlight with Baader UVIR-Block Filter]Chickweed, lamium, plantago, veronica, ranunculus and trifolium were also growing on this grassy corner. (Not all are seen in this photo.) Ultraviolet Light [f/11 for 1/3" @ ISO-800 in Sunlight with Baader UV-Pass Filter]The Dandelions show up best in UV. Visible Light [f/8 for 1/750" @ ISO-400 in Sunlight with Baader UVIR-Block Filter] Ultraviolet Light [f/8 for 1/1.5" @ ISO-400 in Sunlight with Baader UV-Pass Filter] Infrared Light [f/8 for 1/750" @ ISO-400 in Sunlight with B+W 092 IR-Pass Filter]Dandelions are fascinating in IR light. Both the stamens and the faded, folded up abaxial side of the flowers are IR-absorbing. Link to comment
Andrea B. Posted March 15, 2017 Author Share Posted March 15, 2017 SET 3Middletown, New Jersey, USA26 April 2015Wildflower Equipment [Nikon D600-broadband + Nikon 105mm f/4.5 UV-Nikkor] Visible Light [f/11 for 1/25" @ ISO-100 in Sunlight with Baader UVIR-Block Filter] Ultraviolet Light [f/11 for 5" @ ISO-400 in Sunlight with Baader UV-Pass Filter] Infrared Light [f/16 for 1/3" @ ISO-100 in Sunlight with B+W 093 IR-Pass Filter] Link to comment
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