Freelancers rig camera 3D models by creating custom control interfaces (e.g., pan/tilt widgets, zoom sliders) in software like Blender or Maya, then linking these controls to the camera’s transform (position/rotation) and lens (focus/aperture) properties.
This simplifies animation for clients—animators use intuitive, real-world-like controls instead of raw parameters, cutting down on revision time and making the rig easier to use.
If starting out, try Blender’s "Drivers" or Maya’s "Set Driven Key" tools for basic setups, and test the rig with short animation clips to ensure controls work as expected.