In the technical data the field of view is always given for one thousand meters, e.g. 56m/1,000m. This means that from a distance of one thousand meters the field of view is 56 meters wide. This information is sometimes also specified in degrees. With these conversion formulas you can calculate the information yourself. The factor 17.5 means the visual field in meters with a field of view of 1°.

Field of view from 1,000m = degrees (true) x 17.5

Degrees (true) = field of view from 1,000m / 17.5