We're at a turning point - as of last year, over half of new phone models have a dual camera on their backs. The last time something like this happened was in 2003, except then the switchover was from "no camera" to "one camera". If you look closely, you'll see the green sprout that starts in 2017 and stretches to 2018 - this represents the phones with a triple rear camera. We expect the number to grow this year and keep getting bigger and bigger as time goes on. We don't see this trend reversing. Mechanical zoom is unfeasible on current mobile. Also, utility modules - things like...
Source: https://www.gsmarena.com/counterclockwise_counting_cameras_to_say_goodbye_to_the_age_of_single_camera_phones-news-35548.php
