Datalogic Matrix 120 Product Reference Manual page 91

Example:
The FOV for a Matrix 120 310-xxx at a reading distance of 100 mm is:
FOV = 2 [(100 mm + 8 mm) * tan (41°/2)]  81 mm
H
FOV = 2 [(100 mm + 8 mm) * tan (32°/2)]  62 mm
V
Product Reference Guide
Figure 58 - Reading Distance References
FOV Calculation
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