Monday, April 8, 2019

Apache beggarticks - Bidens ferulifolia in reflected ultraviolet photography using an UV-LED IX

Today more shots of that long blooming spring flower "Rockstar" hybride Apache beggarticks - Bidens ferulifolia in reflected ultraviolet photography. All shots were done at f8 in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight as well as a Convoy S2 UV LED with Nichia UV chip inside.

This is to show how useful such an UV-LED can be, in case not enough sunlight is available. This UV torch has been equipped with a front UV transmission filter to cut away all visible blue light.

[click on image to see a larger one]

Human vision:

Reflected UV with sunlight:

Reflected UV with filtered Convoy S2 UV LED :

Bidens has a strong visible UV pattern, its petal tips are UV bright around 365nm, its center is quite UV dark, so this is an ideal test object to test out this small Convoy S2 UV-LED torch, which strongly enhances the visibility of this UV pattern.

Personally I prefer sunlight, but if this is lacking, or a very sharp image is needed, the nearly monochromatic UV-Light is an ideal and easy to get UV light source.

I have written about Bidens previously HERE
Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site