Field of View Calculator

The Field of View (FOV) Calculator is used to help identify several field of view metrics associated with DRS Infrared’s major products including:
  • Tamarisk®320
  • Tamarisk®640
  • UC 640 17-micron
  • Zafiro®640
Use this tool to determine the number of "pixels on target" given a particular product, lens selection, and range. The FOV Calculator presents the number of pixels on screen for a given subject, whether a dog, person, truck, or airplane, as well as maximum ranges for subject detection, recognition, and identification.
Download Field of View Calculator
Click here to download the DRS Infrared Field of View Calculator. Microsoft Excel is required to be installed for the Calculator to operate properly.

A zip file will be downloaded that contains the calculator spreadsheet and associated imagery. Extract the embedded files into a single directory. Open the "Field_of_View_Calculator_rev*.xlsm" file to begin using the FOV Calculator.
Instructions on Using the FOV Calculator
IMPORTANT: Enable macros within Microsoft Excel for the FOV Calculator to operate.
  1. From the "Available Camera Models" drop-down in cell B-5 on the FOV Calculator tab, select the product on which the calculations will be based. The "Camera Information" section to the right will populate with information, such as pixel pitch (size) and resolution, for that camera.
  2. From the "Available Lenses (HFOV)" drop-down in cell B-16, select the lens to use with the product chosen in step 1. Lenses are represented by the number of degrees in their horizontal field of view. Only lenses that work with the product selected will be displayed. Note that lenses with smaller horizontal fields of view generally see farther but more narrowly.
  3. In the "Range of Object (m)" field in cell B-31, enter the expected number of meters between the camera and the subject. This may be as close as 3 meters if watching a doorway, 25 meters if watching a courtyard, or 100 meters or more if watching a fence line, large parking lot, or airport.
  4. Finally, either input the estimated size of a subject (in meters) in cells B-39 and C-39, or select a standard subject, such as dog, human, truck, or airplane, from the drop-down in cell B-44. Selecting a standard subject will automatically populate the sizes for that object in the formula.
  5. Once the object size has been entered, the "Range to Object" section to the right of the final inputs will display the "pixels on target" information and the maximum ranges for object detection, recognition, and identification for this particular set of inputs.
Download FOV Calculator