| title | layout | mathjax | permalink |
|---|---|---|---|
FOV calculator |
default |
true |
/fov |
If you are not sure about your camera, you can use the following form to estimate its focal value.
Simply use your camera in capture mode, facing a plane (e.g. the floor or a wall), and measure the distance from the camera to the plane, as well as the size of the diagonal of the image on the plane. Use 1920x1080 resolution.
Camera distance to the plane (m)
Size of the diagonal, in 1080p (m)
Assuming an image with a 1920x1080 aspect ratio, the following are the field of view angles for the camera:
- Width FOV: °
- Height FOV: °
- Diagonal FOV: °
Mounted at a height of 2m, the camera will see the following field dimensions:
- Length at 2m: m
- Width at 2m: m
To see the whole field, the camera should be placed at a minimum height of m.
The proposed setup has a mount point of 2.0m. If the camera height is higher, you may need to adjust the mount point.
<script>
document.querySelector('form#camera').addEventListener('submit', function(e) {
e.preventDefault();
const diagonalPixels = Math.sqrt(1920**2 + 1080**2);
const cameraDistance = document.querySelector('#camera-distance').value;
const diagonalSize = document.querySelector('#diagonal-size').value;
const focalValue = (diagonalPixels * cameraDistance) / diagonalSize;
document.querySelector('#focal-value').value = focalValue.toFixed(0);
updateFOV();
});
function computeFOV(focal, pixels) {
return 2 * Math.atan(pixels / (2 * focal)) * 180 / Math.PI;
}
function updateFOV()
{
const focalValue = document.querySelector('#focal-value').value;
document.querySelector(".widthFOV").textContent = computeFOV(focalValue, 1920).toFixed(2);
document.querySelector(".heightFOV").textContent = computeFOV(focalValue, 1080).toFixed(2);
document.querySelector(".diagonalFOV").textContent = computeFOV(focalValue, Math.sqrt(1920**2 + 1080**2)).toFixed(2);
const fieldLength = 2.45;
const fieldWidth = 1.84;
const lengthAt2m = (1920 / focalValue) * 2;
const widthAt2m = (1080 / focalValue) * 2;
document.querySelector(".lengthAt2m").textContent = lengthAt2m.toFixed(2);
document.querySelector(".widthAt2m").textContent = widthAt2m.toFixed(2);
if (fieldLength > lengthAt2m) {
document.querySelector('.length-2m').classList.add('text-danger');
} else {
document.querySelector('.length-2m').classList.remove('text-danger');
}
if (fieldWidth > widthAt2m) {
document.querySelector('.width-2m').classList.add('text-danger');
} else {
document.querySelector('.width-2m').classList.remove('text-danger');
}
const cameraHeightLength = (focalValue / 1920) * fieldLength;
const cameraHeightWidth = (focalValue / 1080) * fieldWidth;
const cameraHeight = Math.max(cameraHeightLength, cameraHeightWidth);
document.querySelector(".cameraHeight").textContent = cameraHeight.toFixed(2);
if (cameraHeight > 2.0) {
document.querySelector('.camera-height-alert').classList.remove('d-none');
} else {
document.querySelector('.camera-height-alert').classList.add('d-none');
}
}
document.querySelector('#focal-value').addEventListener('keyup', updateFOV);
document.querySelector('#focal-value').addEventListener('change', updateFOV);
updateFOV();
</script>