Field of View (FOV)
Field of View (FOV) refers to the visual angle of a lens. For Optris IR cameras, depending on the lens, this ranges from 4° (telephoto lens) to 90° (wide angle lens). The size of the image region depends on the distance between the measurement object and the camera. Accordingly, the image section that an individual pixel captures increases or decreases.
In this regard the following terms are of significance:
Instantaneous Field of View (IFOV)
IFOV describes the size of an individual pixel on the measurement surface. It can be calculated based on the pixel size, the distance to the measurement object, and the vertical and horizontal visual angle of the lens.
Measurement Field of View (MFOV)
The MFOV indicates the recommended minimum object size. This corresponds to the measurement field section of 3x3 or 2x2 pixels on the measurement object. The calculation is done in the same way as for the IFOV for a pixel field of 3x3.
Horizontal Field of View (HFOV)
The HFOV describes the horizontal dimensions of the measurement field in the measurement object plane. It can be defined based on the horizontal dimensions of the detector, the distance to the measurement object, and the horizontal visual angle of the lens.
Vertical Field of View (VFOV)
The VFOV describes the vertical dimensions of the measurement field in the object plane. It can be calculated in the same way as the HFOV based on the vertical visual angle and the vertical dimensions of the detector.
Diagonal Field of View (DFOV)
The DFOV indicates the diagonal dimensions of the measurement field in the object plane and can be calculated based on the HFOV and VFOV.
There is an online calculator available to help you calculate the individual fields of view of Optris infrared cameras.