Field of view
This is a parameter of the thermal camera lenses that describes the size of space when taking a photo of an object. Most often it is measured in degrees. Simple geometry is used to calculate the basic field of view parameters. The smaller is the field of view angle, the further you may move away from the object without loss of image quality.
The bigger the field of view, the better the thermal imager works.
Zoom Capacity
Optical multiplicity and digital zoom are used to obtain a detailed image of objects at a great distance. Optical multiplicity for portable thermal camera lenses usually does not exceed 4-5x, and digital zoom – 2x/4x/8x. On average, you can increase the ratio to 20x. The minimum multiplicity provides a wide field of view and displays the real size of the target.
Resolution and pixel size
The main parameter of the thermal camera lensesdetermines its sensitivity and image quality. The larger the size and resolution of the sensor, the more temperature points are displayed. At a resolution of 160×120 pixels, a thermogram of 19,200 pixels is displayed, and at a resolution of 320×240 – 76,800. The maximum value for commercially available thermal imaging cameras – 640×480 pixels, forming a picture of 307 200 points.
Wavelength
A spectrum of thermal radiation – invisible infrared range – 780-100 thousand nm wavelength.
You should therefore pay attention to the wavelength when purchasing a thermal camera lenses. It is important to realize that the bigger the wavelength, the better your thermal camera lenses will perform.
Calibration time
Calibration of the image allows you to equalize the temperature background of the microbolometer and eliminate deficiencies in the image (such as vertical stripes, “frozen” outlines of objects, etc.). Shortcomings appear in the process of operation of the microbolometer, as well as due to heterogeneous heating of the microbolometer. Calibration intervals depend on the duration of operation: the longer the thermographic instrument runs in continuous mode, the less calibration is required.
This parameter should be as small as possible. The faster the calibration is done, the better.
Display size
Why do I need a large display of my thermal camera lenses? First of all – the bigger the display, the less load on your eyes. This is because the bigger the screen, the more pixels it has. The best thing about modern screens is a minimum of 1000 pixels and, of course, the expansion. Take 1280×960 pixels. This is good!
Lenses
The thermal camera lenses differs from lenses of other devices operating in the visible spectrum of electromagnetic radiation. The lens of the thermal camera lenses must transmit thermal radiation, so it is made of germanium (Ge). This material is transparent to infrared waves.