How Does LiDAR Work?

LiDAR is a type of time-of-flight camera. Normal smartphone cameras measure depth with a single light pulse. However a LiDAR sensor sends waves of light pulses out in a spray of infared dots. Each one is measured with the sensor, which creates a field of points and allows the sensor to map out distances. Using these points, the device can “mesh” the dimensions of the area or space and the objects in it. These pulses are invisible to the human eye, but you can see them with a night vision camera. One of the neat little features of the sensor is allowing users to measure the height of a person. Measuring lengths and heights was also available on previous versions of the iPhone, but the built-in LiDAR sensor on the latest iPhones makes this more accurate and precise.

Measuring Height Using the Measure App

Apple’s built-in Measure app allows you to measure the height of a person accurately.

  1. Open the Measure app on your iPhone.
  2. Click on the Measure tab from the bottom of the window.
  3. Make sure the person’s entire body is within your screen.
  4. You’ll see a dot appear on the screen, which is used to measure height and length. Tap on it and drag it to the top of the subject’s head. This should automatically tell their height.
  5. Tap the shutter button to take their photo (if needed).
  6. Tap the image in the lower-left corner to save the photo, then tap Done. Save the photo to Photos or Files. That’s it! Using this handy feature, you can easily measure the height of anyone using your iPhone. If you’d like to re-measure the person, make sure to point the iPhone away before pointing it toward them again. This will reset the previous height measured. Looking for more useful tricks for your iPhone? Try using your iPhone as a mouse for your Mac, which you should find interesting.