How to turn on depth effect on iPhone 7plus if it stops working

Hi there alkaline99,

We can help with the issue you're seeing with Depth Effect on your iPhone camera. You'll want to be sure you have a subject in the frame of your camera and move closer or further away until you see the Depth Effect box turn yellow. Also, try turning off the flash.

To use Portrait mode, open the Camera app and swipe to Portrait mode. Move farther away from your subject if the app suggests it. When the Depth Effect box turns yellow, take the picture. 

Have a look at the 'Portrait' section here to learn more: Use camera modes on your iPhone, iPad, and iPod touch

Take care.