Field of view
How wide a view you get, in degrees. A wide view makes scanning for animals faster; a narrow one usually means more magnification.
What it means
Field of view (FOV) is the angle of the scene the device shows at its base magnification, usually given in degrees as horizontal × vertical, such as 12.5° × 10°. Some makers give it as feet or meters across at 100 yards or meters instead.
It is set by the sensor’s physical width and the lens: a wider sensor or a shorter lens gives a wider view. Most thermal scopes on this site sit between about 7 and 13 degrees across. Handheld monoculars mostly run from about 8 to 18 degrees, with a few near 25. Tube night vision is much wider, commonly 40 degrees.
What it changes in the field
A wide view lets you sweep a pasture quickly and keep track of a coyote that circles downwind. A narrow view shows more detail on one animal but takes many more sweeps to cover the same ground. Hunters often describe a scanner under about 7.5 degrees as tight.
That is why many callers carry a wide scanner for finding animals and use a narrower rifle unit for confirming and shooting.
What to look for
- Match the view to how you hunt: wide for scanning open country and close cover, narrower for long, known shots.
- A 640 sensor gives a wider view than a 384 with the same lens and the same detail on the animal. That is often the best reason to pay for 640.
- Make sure the figure is at base magnification. A few makers print one number without saying at what zoom.
How we use it on this site
We turn the field of view into field width: feet of ground across the screen at 100 yards. A quick rule: feet across at 100 yards is about 5.2 × the horizontal degrees. A 7.5° unit shows about 39 feet; a 17.5° unit, about 92 feet. Wider scores better in the spec table.