Off Topic Camera and resources for improving Candid videos

[oliver21a]

Browsing the public/exhibition section on this forum and going through the Candid Street ass collection/ upskirt videos. I am always intrigued by how and which camera the user is using. I would like to learn the technique and the hardware to use it in public. I have only ever tried using mobile apps like Background Video Recorder and apps similar to that. It makes it easy to record discreetly but the quality is horrendous and not even close to what I see on those posts. Plus the camera angles can't be achieved without being obvious. If someone could help.