Start with the requirements of your application to determine the lens. Download the IRCameras FPA Calculator which calculates the field of view (FOV) based on your sensors format (number of pixels in horizontal and vertical dimensions and pixel size) and lens focal length:
Click here to download the IRCameras FPA Calculator (XLS, 100K)
In addition, our FPA Calculator allows calculating ideal MTF curves for your sensor and lens as well as shows the MTF of the sensor+ lens combination. In addition to lens focal length, you’ll also need to be sure that the lens is designed for your applications spectral region and that the f-number gives you enough photons (larger f-numbers take up less space, but have less light throughput and have lower MTF).
*nBn Focalplane arrays from Lockheed Martin-Santa Barbara Focalplane