Beyond the visible light spectrum.
Infrared photography has given us the ability to record what the eye cannot see. As humans our eyes are sensitive to a limited band of wavelengths, between 400nanometres (the blue spectrum) and 700 nanometres (the red spectrum) known as visible light.
X-rays are a form of electromagnetic radiation that we cannot see, because it is not in our visible light spectrum. We can however record it using photography. Below are images by Nick Veasey who specialises in X-ray art.
Man and Machine
Ultraviolet rays are at the opposite end of the spectrum to Infrared rays. Whereas infrared falls off the red end of our visible light spectrum, ultraviolet falls off the violet end of it. Below are some examples of Ultraviolet photography.
Below is the above flower as seen to the human eye.