Field of view is described as the area that is viewed or seen clearly through the magnifying lens when it is at its focal length. As the lens magnification increases, lens diameter and thus the field of view decrease. This is a rule that is restricted by physics, again as magnification increases, lens size and field of view decreases. At (5x) magnification power the typical field of view is roughly 1.5 inches. At (10x) power it is about .6 inches. As you can see there is an inverse relationship between lens power and lens field of view. We recommended to use lower power lens for scanning or reading large surface areas and a high power lens for inspection and detailed scanning and inspecting very small areas.