I am trying to compile Frequently Asked Questions ( FAQ) about Thermal Imaging System or Thermal Camera. I will keep updating this FAQ when I see a relevant question on it.
Question: What is Thermal Camera ?
Answer: Thermal Camera is that type of camera which ‘produces’ or ‘renders’ images in visual from ( visible to human eyes) from IR ( Infrared) Radiation of objects. It works exactly same as any normal camera or visible camera as in Mobile Phone, or DSLR. But unlike normal camera, it is sensitive to “infrared radiation” which is invisible to human eye and the then it produces/computes digitally a image from it making it visible to human eye. A thermal camera has same elements/components of any normal camera. You may want to read more about Thermal Camera here.
Question: How is thermal camera different from normal camera ?
Answer: I would say, there are two major differences between Thermal Camera and a Normal Visual Camera.
1. Thermal camera produces a pseudo image from infrared radiations emitted by objects and its surroundings while a visual camera produces images from reflected light on the objects and its surroundings.
2. Technically, both infrared radiation and light are similar electromagnetic radiation with different wavelengths. Light is visible to human eye while infrared is not. Also, light has color which human eye can distinguish from one color to another while infrared has no such property. So, while people may have seen colored thermal images or videos, those are not real colors, but pseudo colors, produced digitally using thermal imaging software.
There are many differences in their applications. For example, normal camera or visual camera will not be able to produce any image in absence of light while thermal camera will as its not dependent on light for creating an image. So, thermal cameras can work as night vision cameras in a non-intrusive way. We will keep updating about various applications of thermal camera in future in this blog!
Question: Why are Thermal Cameras very expensive compared to visual camera while having much lower resolution?
Answer: Its difficult to answer this question, but I think, its mostly because of technology as well as demand and supply. The cost of sensors of thermal is expensive like normal camera and every thermal camera needs to be calibrated which requires days, not hours. Also, calibration process has to be preformed by highly skilled technician.
But unlike flagship smartphones whose prices seem to be going up regularly, prices of thermal cameras are coming down as the demand is going up. So, with COVID19, thermal cameras are in demand, so most probably, prices of thermal camera may come down a bit.
Question : What is cooled and un-cooled Thermal Imaging camera ?
Answer: Cooled Thermal Imaging cameras are those whose sensors are kept at a fixed temperature, normally in much cooler than ambient temperature. Un-cooled Thermal Imaging cameras are not cooled and normally uses ambient compensation to produce good images. Normally, cooled cameras produce better images and more expensive that un-cooled ones.
I will put more questions and answers in next update!