Our experienced application engineers ensure competent and reliable customer service in the field. In addition, Optris works closely with numerous distribution partners worldwide.

Field ofview human eye

The DFOV indicates the diagonal dimensions of the measurement field in the object plane and can be calculated based on the HFOV and VFOV.

Field ofview camera

The MFOV indicates the recommended minimum object size. This corresponds to the measurement field section of 3×3 or 2×2 pixels on the measurement object. The calculation is done in the same way as for the IFOV for a pixel field of 3×3.

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.

Field ofview definition microscope

Since the SRF also depends on where the measurement is taken within the image section, in the Final Inspection Report for its Precision Line infrared cameras Optris states the values for the center of the image as well as for all four corners. The spatial frequency is 9.8 Lp/mm.

The MTF is measured by, for example, recording a line grid with the camera. The brightness distribution of such a grid corresponds to a sinusoidal curve. The width of the line pattern (line pairs per millimeter – Lp/mm) describes the so-called spatial frequency. The MTF is a function dependent on the spatial frequency, which is defined as the ratio between the amplitude of the sinusoidal curve on the image, and the original sinusoidal curve. The value is always between 1 (optimal transmission) and 0. In contrast to an optical camera, infrared cameras measure thermal contrast. This is called SRF (Slit Response Function).

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.

Field of viewsvs fov

Field ofview calculator

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.

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.

The Modulation Transfer Function (MTF) describes how well a camera can represent the detail contrast of an object in the image.

Our experienced application engineers ensure competent and reliable customer service in the field. In addition, Optris works closely with numerous distribution partners worldwide.