The dandelion in the visible spectrum:

The dandelion in UV-A as the camera records it:

The dandelion in shifted colors; green, blue, and ultraviolet displayed as red, green, and blue:

The wide spectrum dandelion; red, green, blue, and ultraviolet compressed into the visible spectrum:

An alternate wide spectrum; red, green, and blue are compressed into R & G, and UV-A is placed in B.

It’s a start, but I still have some technique to work out. The lens I am currently using has a large focus shift between visible, ultraviolet, and infrared; and I still haven’t perfected my technique of compensating for the focus shift. The pattern on the dandelion is clearly visible in the UV-A image, but not as clear as I would like, but is actually much clearer than the other two dandelions I took pictures of at different times of day. For much more dramatic examples of dandelions in ultraviolet, see Bjørn Rørslett’s classic example, and Oleksandr Holovachov’s example.

My first experiment was to compress the full IR-visible-UV range into one picture, with each of the five channels equally weighted:

Since I plan on using wide spectrum photography for plants, the IR-A channel isn’t particularly useful. This is because flowers and leaves are often nearly uniformly reflective in the IR-A range. So I compressed the visual range + UV-A into one image:

Since many insects have a visual spectrum shifted to shorter wavelengths than we do, I also created a shifted version. A quick way to do this is by replacing red with green, green with blue, and blue with ultraviolet:

Since the color replacements are arbitrary, I made a version that keeps the leaves green by making a version with the green and blue in place and the red replaced with ultraviolet:

In the process of inspecting these images and other variations, I noticed that my ultraviolet images probably have less infrared contamination than I initially thought. That’s good. Now, to try my ultraviolet setup on more subjects…

Infrared (IR-A)

Red

Green

Blue

Ultravoilet (UV-A)

The ultraviolet (UV-A) image likely has a large amount of infrared (IR-A) contamination, but I should be able to improve that once one more backordered part arrives.

Photo info: Nikon D70, Micro Nikkor 105mm 1:2.8 D; manual exposure 1/320 to 1/500 second, f/6.3 to f/9, balanced speedlight and ambient, with at least half of the light from cross polarized flashes (SB-600, SB-25) on a flash bracket.

In no particular order, the lenses used are:

• Nikon AF Micro Nikkor 105mm 1:2.8 D
• Nippon Kogaku (Nikon) El-Nikkor 80mm 1:5.6
• Tokina AT-X Macro 90mm 1:2.5

All three photos were shot around f/8.0, handheld on a bright windy day with some clouds using a Nikon D70 set for automatic white balance and manual exposure.

Oh, and no looking at the EXIF data.

It took a while to find one of these for a good price, but I now have an Nippon Kogaku (Nikon) El-Nikkor 80mm f/5.6 enlarger lens. It seems to work well as a macro lens when mounted on extension tubes using a M39→F-mount adaptor. Now I just need to find a 34.5×0.5mm→anything else adaptor and a BR3 reversing adaptor so that I can use filters on it…

Once I tightened the screw, I had to spend a good bit of time aligning the zoom ring and the inner ring to close the lens. Seeing someone else’s description of the proper alignment helped. I eventually realized that the lens was zoomed out a little too far to make everything align. To open the lens, you have to zoom to 70mm, but to put it back together, it is much easier if you back off of 70mm a little. Once I realized this, it lined up easily, and the lens is back to the way it should be.