Wednesday, August 13, 2014

150mm Micro reproduction lens for reflected UV photography

Today about a recent find for UV photography, a high resolution (approx. 150-200 lpm) 150mm micro documentation lens, which I have tested positively for UV use. Of course it shows quite some restrictions, but I'm happy about finding such lens in such longer focal length (150mm), which allows for better working distance in some circumstances. All shots were done it studio. Lens for comparision was my CERCO 94mm quartz fluorite lens. Light source was a Xenon flash. All shots were done at about f8.

[click on image to see a larger one]

Test images using Baader-U filter for reflected UV photography and as a target a Rudbeckia fulgida flower. Adjusted for comparison to even out focal length differences. Individual white balance set per image.

Cerco 94mm (left), Micro Documentation lens (right)

The micro docu lens does quite well and seems to be quite a sharp lens, even when used for UV.

Now about the spectral transmission:

It gets obvious that this micro docu lens only transmits down to about 350nm, but has sufficient transmission around 360nm to make flower UV patterns visible.

So to summarize I would call that a nice find, which adds to the repertoire of suitable UV lenses, especially since it has very high resolution also in UV.

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

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