If you have a smartphone with more than one camera lens, follow these steps to find the right lens and take a good heart rhythm measurement:
- Start with the lens closest to the flash.
(If your smartphone has more than one lens at the same distance from the flash, try them one after the other.)
- Start measuring by tapping the red heart in the app and then place your finger on the lens for 15 seconds.
- You can tell that the measurement has started because the seconds start counting down and your heart rate is displayed.
- If the measurement doesn’t start, try the next lens.
Tip: You don’t need to cover the flash itself. It may warm up during measuring.