If you are thinking about purchasing a new camera for 4K video, a great choice just might be something you already own!
I used my Samsung S9+ mobile phone to record these clips that you see here. The camera will record in 4K video at 60 FPS which is the format that I used for all these shots. The phone was mounted on my Zhiyun Crane M2 gimbal which definitely help in image stabilization. However, almost any gimbal would help and prices start around $100.
The choice of recording in 60 FPS was used because I like to have the option of slowing the video down in post-production. This technique can be used to create a slow-motion effect or just as a method of smoothing out an otherwise shaky video. Davinci resolve is a free program to achieve this effect and there are numerous tutorials available on YouTube.
A few downsides to using a smartphone for recording come along with this. The phones are prone to overheating when recording 4k video. This may limit you to recording times of a few ...