Field ofview Formula

Notice that there is a line of light perpendicular to the slit. While looking through the slit, rotate the pencils until they are horizontal, and notice that the line of light becomes vertical.

To calculate the FOV requires the sensor size and the focal length of the lens: h = Sensor Size F = Focal Length of the Lens

Field ofview synonym

How can you find the origin of these lines? Rotate the light source and notice that the lines of light do not rotate. Rotate your head and notice that the lines do rotate. Hold your hand or an index card in front of your eye so that it doesn’t quite block your view of the light source (click to enlarge diagram below).

Thin objects, such as a strand of hair, also diffract light. Light that passes around the hair spreads out, overlaps, and produces a diffraction pattern. Cloth and feathers, which are both made up of many smaller, thinner parts, produce complicated diffraction patterns.

Focal length (F) is the distance between the center of a lens and its sensor. The size of the lens is the aperture size.

Field ofview human eye

Human eyefield ofview in mm

Field ofview calculator

The black bands between the blobs of light show that a wave is associated with the light. The light waves that go through the slit spread out, overlap, and add together, producing the diffraction pattern you see. Where the crest of one wave overlaps with the crest of another wave, the two waves combine to make a bigger wave, and you see a bright blob of light. Where the trough of one wave overlaps with the crest of another wave, the waves cancel each other out, and you see a dark band.

A wide angle lens or smaller lenses produce a greater field of view and captures more objects in a scene enhancing your ability to cover larger and wider areas such as foyers, parking lots or warehouses.

If you look closely you may see that the line is composed of tiny blobs of light. As you squeeze the slit together, the blobs of light grow larger and spread apart, moving away from the central light source and becoming easier to see. Notice that the blobs have blue and red edges and that the blue edges are closer to the light source.

The narrower the slit, the more the light spreads out. In fact, the angle between two adjacent dark bands in the diffraction pattern is inversely proportional to the width of the slit.

Fixed: a fixed camera focal length provides an Angular FOV which is permanently set and cannot be adjusted by the user. Varifocal: the camera focal length can be manually adjusted by the user. Generally, this is done manually with screws or dials. At Lorex we have motorized varifocal cameras that allow you to digitally zoom using your phone or NVR without losing details. These lenses provide flexibility and customization for your camera image needs.

Notice that you still see a full circle of lines radiating out from the light source. The effect actually happens in your eye, as lines of light are spread out onto your retina by imperfections in the tissues of your cornea.

Field ofview definition microscope

Field of View (FOV) is the maximum observable area that is seen at any given moment through an optical device such as a camera lens. The coverage of the area can be measured using the horizontal and vertical distances to find the diagonal of the area in degrees. Mathematically, the FOV is calculated using the horizontal dimension of the sensor (h) and the Focal Length (F). You can find the camera’s Field of View details in the Specifications sheet. Click here for additional support content including security camera documentation. The Camera Lens, Sensor and Focal Length Focal length (F) is the distance between the center of a lens and its sensor. The size of the lens is the aperture size. These factors affect field of view. A narrower focal length captures more of the scene and displays a larger field of view. A wider focal length magnifies a scene and decreases the field of view. The higher the focal length value the lower the FOV. Types of Camera Lenses Fixed: a fixed camera focal length provides an Angular FOV which is permanently set and cannot be adjusted by the user. Varifocal: the camera focal length can be manually adjusted by the user. Generally, this is done manually with screws or dials. At Lorex we have motorized varifocal cameras that allow you to digitally zoom using your phone or NVR without losing details. These lenses provide flexibility and customization for your camera image needs. The importance of Field of View A wide angle lens or smaller lenses produce a greater field of view and captures more objects in a scene enhancing your ability to cover larger and wider areas such as foyers, parking lots or warehouses. A narrow angle lens or larger lenses produce a smaller field of view; capturing a limited area, but the camera quality image improves in detail. These are designed to monitor a specific object, such as cash registers, entrances/exits, hallways or objects of value. How to Calculate the FOV To calculate the FOV requires the sensor size and the focal length of the lens: h = Sensor Size F = Focal Length of the Lens FOV is represented by this equation: FOV = 2tan-1(h) / 2F Example: h = 4.7mm F = 6mm FOV = 2tan-1(h) / 2F = 2tan-1(4.7)(12) = 2tan-1(0.39) = 2(21.4°) = 42.8°

A narrow angle lens or larger lenses produce a smaller field of view; capturing a limited area, but the camera quality image improves in detail. These are designed to monitor a specific object, such as cash registers, entrances/exits, hallways or objects of value.

Field ofview camera

Light bends when it passes around an edge or through a slit. This bending is called diffraction. You can easily demonstrate diffraction using a candle or a small bright flashlight bulb and a slit made with two pencils. The diffraction pattern—the pattern of dark and light created when light bends around an edge or edges—shows that light has wavelike properties.

Field of viewsvs fov

Stretch a hair tight and hold it about 1 inch (2.5 cm) from your eye. Move the hair until it is between your eye and the light source, and notice that the light is spread into a line of blobs by the hair, just as it was by the slit. Rotate the hair and watch the line of blobs rotate.

Hold up the two pencils, side by side, with the erasers at the top. The tape wrapped around one pencil should keep the pencils slightly apart, forming a thin slit between them, just below the tape. Hold both pencils close to one eye (about 1 inch [2.5 cm] away) and look at the light source through the slit between the pencils. Squeeze the pencils together, making the slit smaller.

Field of View (FOV) is the maximum observable area that is seen at any given moment through an optical device such as a camera lens. The coverage of the area can be measured using the horizontal and vertical distances to find the diagonal of the area in degrees. Mathematically, the FOV is calculated using the horizontal dimension of the sensor (h) and the Focal Length (F).

In a dimly lit room, look at a Mini Maglite bulb with one eye (a candle will not work). Notice the lines of light radiating out from the light source, like the seeds radiating out from the center of a dandelion.

The angle at which the light bends is proportional to the wavelength of the light. Red light, for instance, has a longer wavelength than blue light, so it bends more than blue light does. This different amount of bending gives the blobs their colored edges: blue on the inside, red on the outside.

Look at the light through a piece of cloth, a feather, a diffraction grating, or a piece of metal screen. Rotate each object while you look through it.

You can find the camera’s Field of View details in the Specifications sheet. Click here for additional support content including security camera documentation.

These factors affect field of view. A narrower focal length captures more of the scene and displays a larger field of view. A wider focal length magnifies a scene and decreases the field of view. The higher the focal length value the lower the FOV.