Why Training Matters
An infrared thermal imager in the wrong hands can result in disastrously inaccurate results – and here’s why.
Even with no training at all, expensive infrared cameras will produce impressive looking (but useless) images. This can be difficult to explain without diving into technical concepts that tend to bore all but the most dedicated infrared professionals.
Instead, here’s an analogy that helps show that a number of variables need to be considered to produce high quality images.
To say an infrared camera measures temperature would not be any more accurate than to say a digital camera measures color. Both technologies contain sensors that convert observed wavelengths into an arrangement of pixels, but observed wavelengths don’t always represent the actual value of the subject being photographed. One of the best examples of this can be seen in the image below:
“The dress” above went viral in early 2015 when viewers disagreed over whether it was gold and white, or black and blue. The sensation resulted in numerous articles in scientific journals and has caused an ongoing scientific investigation into how we perceive color.
Early on in the debate, Adobe, an imaging software producer, attempted to settle the score by isolating and analyzing pixel values. Their results were inconclusive. That’s because the photo fails to account for environmental factors and camera settings that cannot be determined by the image alone.
Unknown variables included:
- Lighting – Natural, incandescent, fluorescent, LED, and other light sources can affect the appearance of the subject. Placement of the dress relative to the light source(s) can also introduce shadows.
- Surrounding Colors – A white dress is a blue room will tend to photograph as blue. Similarly, other paint and dress color combinations will show up differently when photographed.
- Dress Material – If the dress is semi-transparent or contains reflective materials it can take on properties of surrounding objects when photographed.
- Camera Exposure – Longer exposures make images appear brighter and shorter exposure make them appear darker.
With a lifetime of seeing in the visible light spectrum, our brains can often correct for factors, such as shadows, that affect colors in a photograph. Even with this ability, colors can sometimes be difficult to determine.
Nobody has a lifetime of experience seeing in the infrared portion of the electromagnetic spectrum, which leaves even the most basic images vulnerable to the same misinterpretation we see in the dress.
Here’s how the dress conundrum relates to thermal imaging:
Without understanding and correcting for environmental factors, material properties, and infrared camera settings, chances are the final image data will be inconclusive at best, and could be dangerously misleading.
Proper training and experience ensures all necessary factors are taken into consideration to produce high quality, accurate thermal images. To make sure you’re getting the best results possible, verify any thermographer you hire is trained to an appropriate level by a reputable organization.