
This was taken in the south west of England with a FLIR 320 by 240 pixel E320 thermal imaging camera. This camera covers a range of 7.5 to 13 µm, which includes a substantial atmospheric window around 10 µm.
2010 marked the centenary of the first published infrared image. This is the Infrared 100 blog, which celebrates that centenary and discusses all aspects of infrared imaging: near and far.
The foveal sensitivity to several near-infrared laser wavelengths was measured. It was found that the eye could respond to radiation at wavelengths at least as far as 1064 nm. A continuous 1064 nm laser source appeared red, but a 1060 nm pulsed laser source appeared green, which suggests the presence of second harmonic generation in the retina.
During the diagnostic research done by means of optical devices equipped with radiation sources from the near infrared range the phenomena indicating the perception possibility of this range by a human eye were observed. In this contribution the initial results of the research of this phenomenon were presented. Sources of radiation applied in laser polarimeters (785 nm) and devices designed for optical coherent tomography (820, 850 nm) were taken into particular consideration. Perception tests with the use of a laser diode generating at the wavelength of 940 nm were also carried out. It was stated that the radiation from the range examined can be recorded by a human eye giving a colour sensation — in practice independently of the wavelength of the radiation beam falling into a retina.I suspect this kind of experiment with lasers falls into the don't try this at home category but it demonstrates that the usual limits quoted for human visual sensitivity are not necessarily the only ones.
This study resolves a long-standing question about the ability of humans to perceive near infrared radiation (IR) and identifies a mechanism driving human IR vision.
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