All About Digital UV and IR. Page 10: Which Software?

The software we use for decoding the digital record of the CCD into useful images, either viewed on a computer screen or printed, has a great bearing on the final results. Digital photography in general needs an efficient workflow in which batch processing is crucial. However, digital UV/IR images don't lend themselves to batch processing because many, if not all, images should be processed and fine-tuned individually.

I have used Bibble (versions 2.5 through 2.99f, and 3.0x), Nikon Capture (versions 1.13 and 2.02), and the NEF plugins for Adobe Photoshop which come with Nikon View (version 4 through 5.1.1). Although I have purchased a licensed copy of QImage Pro, I find the user interface of that software to be quite impenetrable so it will not be discussed further.

As stated more than once in this article, the digital raw file should be considered just as a "negative" waiting to be processed. The first step is getting the colour balance on a pleasing track. Many of the UV or IR shots are delivered straight off the camera with strong color casts, abd corrective measures are needed. A white-balancing during the shooting stage will in most cases not be very helpful, because the software of the camera generally cannot handle UV/IR, and who is to say which colour is the "correct" one? However, the software can and do produce different results, even for such a simple operation as a white-balance ("click-white"). This is not entire decisive for the final result, though, because the image in general has to be processed in several steps, each of which having its own corrective potential.

"Click-White" Operation May Produce Vastly Different Results - The End Result is Your Choice

(Digital IR with 89B filter on a Nikon D1H with 105 mm f/4 Nikkor lens)

Bibble 3.01

Nikon Capture 2.02

In the example depicted above, Nikon Capture produced the most pleasing colour scheme. I find this frequently occurring for digital IR shots, for NEF files obtained by any of the D1-series cameras. It is not a big secret that I personally prefer Bibble for most of my raw file processing, but Nikon Capture has its strong points as well, and in the end the choice must be your own. The programs complement each other and if you can afford this, purchase licensed copies of both.

The next section outlines the processing work-flow to turn a UV flower shot into a useful image. Bibble 3.03 is the software foundation for this example, but similar results may be obtained by Nikon Capture.

This flower (Leontodon autumnale) has a typical two-zoned UV pattern, but the inherent IR contamination of the digital image masks the features to a large extent. Judicious software control is needed to get a better end result. Really this isn't any different than processing a negative into a final print. Since I have many shots of this and similar flowers on film (and digital), I knew in advance how the final colours should look like.

Close-up of a composite flower (Leontodon autumnale), using Nikon D1H with UV-Nikkor 105 mm f/4.5 (f/11, 1/125 sec. @ ISO 800), Hoya U-360 and Tiffen Hot Mirror, SB-140 UV flash. In this case, the hot-mirror filter reduced overall UV sensitivity and should have been left out (this image was a comparison control for evaluating UV potential of another camera, which needed the hot mirror). In a more typical setting, the colours should be better balanced from the onset.

	As typical for UV images, the tonal range is restricted and the picture is perceived as being sombre. The overall reddish cast doesn't do much to improve the situation.

A quick "click-white" operation, based on the central petals, turn the flowers more like I want them. Now, the two-zoned pattern begins to emerge. The picture is still too dark in the lower and middle tone range and colours are not very satisfactory.

The colours are brought into focus by using a combination of hue and saturation adjustments. I prefer using this operation in the earlier processing stages, where the software can compute directly on the raw data with full precision. Alternatively, you could import the file as a 16-bit TIF into Photoshop and perform the adjustments there. A slight increase of the middle tone range gives the final touch to the UV image.

	Hue is adjusted to give more reddish colours, and saturation is enhanced in preparation for the next stage. Bibble allows these operations directly on the NEF file. Nikon Capture provides less fine-tuning of the colours and you might prefer to perform the adjustments in Photoshop instead.

	We also need to bring the tonal range better into accordance with how we perceive images, thus to some extent subduing the stark and sombre impression of the "raw" UV image.
And so, the final image can be displayed