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