Wednesday, July 6, 2011

[UV] whitebalancing using a 35mm wide angle lens for UV

Today I made some experiments using wide(r) angle lenses for shooting reflected UV using my UV sensitive camera.

I had previously written about proper whitebalancing to reach a standardized false color UV palette using a true apochromatically corrected UV lens and also about doing that for other wide angle lenses. Now I wanted to reach about the same "colors" using such a lens which transmits much less UV, in that case here a 35mm c-mount lens.

[click on images to see larger ones]

Standardized reflected false UV "colors" according to the previously described "UV color palette" related to wavelength.

The normal and high intensity palette:



The reflected UV images show a Rudbeckia hirta flower. Left the result before applying my whitebalancing procedure; on teh right after whitebalancing using my ReflectionDisc (and some special in-camera tweaking):

[the colors on the left image are NOT according to the standardized palette!]

Well, as you can see, about the same colors could be reached on the right image, still a little different, as some parts of the spectrum are missing (the shorter wave UV-A sub-bands more specifically, so there is no green as that lens only transmits to about 350nm). Still it gets evident that this Rudbeckia flower has a UV reflection from its petal tips of around 360nm.

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

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos