When Raspberry Pi OS moved from being based on Debian Buster, to Bullseye, the transition wasn’t the smoothest. For many years Raspberry Pi OS used three tools to access the official Raspberry Pi camera. The first two were raspistill / raspivid, which offered control and access to the camera via the Linux terminal.
It was a powerful and flexible means to work with the camera, both could produce video effects and stream video with no extra work. The other means was a community created project called PiCamera. Originally created by Dave Jones, Picamera grew from a community project into an essential tool. Picamera offered a purely Python means to interact with the camera, and being based on Python it also meant that we could mix the camera into our projects.
With the move to Bullseye, we saw Picamera sadly break. Raspberry Pi LTD even went as far as to offer a “legacy” version of Buster with Picamera and security updates. This was a stopgap measure while its developers worked on Picamera2. With the September 2022 release of Raspberry Pi OS we now have a working Picamera2 module that we can use in our projects.