Full-Spectrum Camera Composites

Unlocking the Hidden Spectrum: Building Custom Composite Imagery with Full-Spectrum Photography

Exploring multi-spectral imaging by mapping Infrared Ultraviolet reflectance images into false colors using a modified reflex camera.

Have you ever wondered what the world looks like beyond what human eyes can see?

By default, our eyes (and standard digital cameras) are locked into the narrow strip of visible light spanning roughly 400nm to 700nm. But with a modified full-spectrum reflex camera, that boundary disappears. By removing the internal IR/UV cut filter from the camera sensor, the full range of light—from ultraviolet (UV) all the way to near-infrared (IR)—becomes available to capture.

Figure 1: Full multi-spectral workspace preview with calibrated channel layers.

Mapping the Invisible: UV and IR Channels

When shooting multi-spectral scenes, translating invisible light into a recognizable color image requires a custom mapping process:

• Infrared: Near Infrared light (700nm+) reflects heavily off organic matter like healthy foliage (a phenomenon known as the Wood Effect). 
• Ultraviolet: Ultraviolet light (<400nm) interacts strongly with surfaces, skin, floral patterns, and atmospheric scatter. 

By combining these distinct spectral bands with additive color blending, structural elements that would normally stay hidden suddenly pop into view.

We can do this with this tool i created: https://gmlado.pythonanywhere.com/multichannel/

For example, here I have routed a NIR image to the red channel and the UV reflectance image into the green channel:

Notice how bright green colors correspond to high UV reflectance. Different pigments react different and have distinct absorption and reflection wavelength bands. 

If we have a standard camera  with RGB channels we can extract each and recombine them in the same way, obtaining a visible spectrum image as such:

These images were taken with natural sunlight and a modified  Canon EOS 60D with the the following filters:

1. For Infrared imaging: BAADER IR-Pass Filter 685nm 2" (Item No. 2458386)
2. For Ultraviolet imaging: BAADER U-filter 60nmHBW/320-380nm fully blocked VIS & IR 2" (Item No. 2458291)

Interactive Comparison: Drag the Slider

Slide left or right to compare channel calibration states in real-time.

Figure 2: Adjusting contrast thresholds and windowing levels.

Figure 3: Overlaid intensity colorbars with custom text styles.

Precision Processing & High-Res Exporting

Capturing the raw frames is only half the battle; balancing contrast and outputting publication-ready visuals is where the real magic happens. Using our dedicated web workspace, fully coded in html, we can fine-tune and export the results:

1. Window & Level Fine-Tuning: Each spectral band comes with its own exposure profile. Independent Min/Max sliders let me dial in contrast and black/white clip points channel by channel.
2. Dynamic Colorbars: Quantitative colorbars display exact pixel intensity thresholds directly on the preview. Custom styling controls allow for choosing text colors, bar orientation (vertical or horizontal), and placement.
3. High-Res Composite Export: With a single click, the tool burns in the styled colorbars directly onto the full-resolution composite image at native quality.
4. Channel Miniatures Panel: For technical documentation or scientific write-ups, there is an option to export a side panel featuring grayscale thumbnails of each individual UV/IR input frame alongside the main composite.

Figure 4: Full composite render featuring burned-in colorbars and the optional side panel with channel miniatures.

Interactive Comparison: Drag the Slider

Slide left or right to compare channel calibration states in real-time.

Interactive Comparison: Drag the Slider

Slide left or right to compare channel calibration states in real-time.

What's Next?

Full-spectrum composite photography opens up endless creative and analytical possibilities—from revealing hidden patterns in flowers that attract pollinators to capturing surreal, otherworldly landscapes.

Stay tuned for upcoming galleries as I explore new subjects under modified UV/IR multi-spectral lighting!