Here at TheVJ.com we love smartphones. We believe that they represent the single most important technological innovation to video in recent years. No other single piece of technology has had so much impact on the video industry, and more simply the ways in which we create and consume video.
While you certainly can make professional quality video with nothing but a smartphone, there are plenty of accessories that you can add to make your image and sound even better. While the lenses on smartphones are in and of themselves pretty good and can shoot in full HD and in some cases 4K, they can be limiting simply because of their size. Attachable lenses can give you a more dynamic and cinematic image. Additionally, the microphones on these phones are often not powerful at all and do not get a great image. Don't fear though, there are plenty of accessories for these issues and more! Check out this video from Film Riot highlighting the 13 best you should have in your kit.
Now everyone is different and what works for some people may not work for you so the key is to find a kit that works for you and makes your video as good as it can be.