How to take photos of people blowing out birthday cake candles with D90?

First of all, good light is required, so the camera is set to continuous focus mode and shooting mode is set to continuous shooting, and then just press the shutter when you start blowing out candles.

If it is a very dark environment, it is not easy. First, turn on all the lights and focus on the person who blows out the candles. After focusing, set the camera focusing mode to manual, and then stop blowing candles to take pictures, otherwise the photos will be blurred. At this time, you can turn off the lights, set the camera to automatic shooting mode, press the shutter at the moment when you see the best time to blow out the candles, and the flash will automatically start to take a photo. But not continuous shooting, because it takes time to charge the flash.