Infrared Camera (IR)
Electromagnetic Radiation with a Wavelength Longer than that of Visible Light

Ghost Hunting Equipment: IR Camera
Electromagnetic Radiation with a Wavelength Longer than that of Visible Light

Infrared Cameras are used in ghost hunting to view spirits that sometimes cannot be seen with the human eye. The theory is that spirits are more easier seen through IR light rather then UV light.

Another theory states that spirits move more quickly through our dimension and because of this a high speed object would be easier to film using a high frequency short wave source and that composition of spirits may be more sensitive to reflecting IR light. 

Infrared energy is just one part of the electromagnetic spectrum that encompasses radiation from gamma rays, x-rays, ultra violet, a thin region of visible light, infrared, terahertz waves, microwaves, and radio waves. These are all related and differentiated in the length of their wave (wavelength).

All objects emit a certain amount of black body radiation as a function of their temperatures. Generally speaking, the higher an object's temperature is, the more infrared radiation as black-body radiation it emits.

A special camera can detect this radiation in a way similar to an ordinary camera does visible light. It works even in total darkness because ambient light level does not matter.

Images from infrared cameras tend to have a single color channel because the cameras generally use a sensor that does not distinguish different wavelengths of infrared radiation.

Color cameras require a more complex construction to differentiate wavelength and color has less meaning outside of the normal visible spectrum because the differing wavelengths do not map uniformly into the system of color vision used by humans.

Infrared Cameras

Using infrared light, the environment remains
dark to the human eye. To the camera, it appears illuminated.

This virtually eliminates the capture of false orbs due to dust.

Also, the investigation is not compromised by the constant popping of camera flashes.

Sometimes these monochromatic images are displayed in pseudo-color, where changes in color are used rather than changes in intensity to display changes in the signal.

This is useful because although humans have much greater dynamic range in intensity detection than color overall, the ability to see fine intensity differences in bright areas is fairly limited.

This technique is called density slicing. For use in temperature measurement the brightest (warmest) parts of the image are customarily colored white, intermediate temperatures reds and yellows, and the dimmest (coolest) parts blue.

A scale should be shown next to a false color image to relate colors to temperatures. Their resolution is considerably lower than of optical cameras, mostly only 160x120 or 320x240 pixels.

A Wireless IR Camera Setup

A test run of camera infrared wireless system
hooked into a laptop computer.

Thermographic cameras are much more expensive than their visible-spectrum counterparts, and higher-end models are often deemed as dual-use and export-restricted.

In uncooled detectors the temperature differences at the sensor pixels are minute; a 1 °C difference at the scene induces just a 0.03 °C difference at the sensor.

The pixel response time is also fairly slow, at the range of tens of milliseconds.

* Tripods are recommended

IR Camera Tips

  • Make sure you are using fresh batteries in your IR camera. Batteries that are not fully charged can result in poor performance.
  • Be aware that most 'orbs' that are seen can be attributed to dust, bugs and other debris in the air.
  • Use a tripod if possible. This will provide a steady view.
  • Attempt to show a good field of view in the IR camera. It is best to zoom out to the point that you can see a large portion of the area. Zooming in too close will usually provides poor results.
  • Most IR cameras offer a feature called 'image stabilization'. This is recommended so the video is not shaky during playback.