Blens

Blens is a simple camera control add-on for Blender designed to help artists achieve realistic visualizations as if using real lenses on a 35mm or Full-Frame camera.

Out of the box, when installed, it fixes Blender's FOV for any aspect ratio by automatically calculating the sensor size based on the render resolution.

The add-on adds an intuitive and easy to use sidebar panel that seamlessly integrates with Blender's interface and gives two extra functionalities: allows the user to set the resolution per-camera, so each camera can use a different resolution and aspect ratio in the same scene, and lets you select from the most common Focal Length and F-Stop lens values in real-life photography.