We have found that with our thermal imaging system, white-hot works better during daylight situations or when solar loading occurs. We primarily utilize black-hot in the evening or during optimal thermal conditions. Since our mission often dictates we work in non-optimum thermal conditions, we are continually making adjustments to the gain and contrast of our system as well as changing polarity to get the best possible image.

During the course of our casework, we have learned that with our particular imaging system we can better profile a target vehicle in black-hot. White-hot tends to produce a "halo effect" when a car heats up particularly in the area of the front wheel wells because of the heat emanating from the tires and engine. This heat tends to wash out distinguishing features that may help us determine one vehicle type from another and is particularly useful during discreet surveillance’s. In black-hot, we can also better distinguish whether windows are rolled down or not, which may give us a "heads up" on imminent activity, particularly in kidnapping or extortion cases.

One evening while our target was stationary and we had some down time, we began looking around the nearby environs for areas of thermal contrast that we use to aid our operators in object recognition. While operating in black-hot, we happened upon a massive plume following the shoreline of a river. We traced the emissions to the point of entry and found that they were being released by a steam-generated power plant. The enormous contrast of the heated outflow against the much colder river water was particularly evident, and we were able to track the temperature difference well downstream. For comparison purposes, we decided to try changing the polarity of our imager to white-hot. To our amazement, the aforementioned stark contrast in water temperature practically disappeared! Had we been searching for just such a scenario in an environmental-sensitive matter, we may have never found it.