Infrared Photography

A picture of a cat shot with an infrared camera

Introduction:

How often do you consider how hot certain objects or creatures are? What parts of a whole have more heat energy than others? Using the naked eye it is quite difficult to tell or nigh on impossible. However, infrared radiation is emitted by most objects that have thermal energy. Using special cameras and sensors it is possible to see the differences in infrared radiation being put out by different things. By doing so useful data can be gathered to be used by scientists, surveyors, and many other professions to help them with their work.

IR image of a ceiling vent using a color display.

IR image of a ceiling vent using monochrome display.

Control image of ceiling vent shown above.

Method:

When taking infrared pictures or video there are a few things to understand. First, a decision has to be made on whether to use a monochrome color scheme or a poly-chrome color scheme. It is easier to notice different objects in poly-chrome, but it is easier to see a difference in temperature in monochrome (though in the end it comes down to personal preferences. Next one needs to note the scale slider on the display (right side on the images above), it will change depending on the focus of the image, as an object much hotter or colder than an object focused on before will need a different scale to properly show the temperature range. It is also a common error to confuse the data when looking at glass, as it does not allow infrared radiation to pass through and will reflect it as shown in the image below.

IR camera pointed at glass door, note the heat signatures of the participants reflected in the glass.
The individual on the other side of the door is only visible due to overlay tracing settings.

From here it is time to go out and take photos to begin to understand how IR works.

Tree with individual in front of it captured in IR.
Note how the leaves reflect the infrared better than the trunk.

Regular photo of image above.

Discussion: 

Infrared photography is very useful for many different applications. It lets firefighters look for hot spots in fires, rescue teams to find head signatures, nature photographers use it to help locate specimen and much more. Being able to use IR lenses to capture parts of the light spectrum humans can't see lets data be gathered in a way that was not possible in the past. By learning how to properly gather and use that data, an individual or team can increase their proficiency in many different tasks.

Conclusion: 

Infrared is used for many different applications. It lets individuals gather and extrapolate data in a new way. However, it is important to know it's limitations and how it works, or data gathered could be confusing or useless. By having an understanding of how IR works, an individual will be a much more effective worker.