fSpy

The application lets users extract camera parameters from a single photograph, reconstructing the original lens settings such as focal length, sensor size, and orientation. By aligning a virtual camera to the image, it produces a matching perspective that can be used for 3‑D composition or visual effects. The tool works on macOS, Windows, and Linux, and is distributed as open‑source software at no cost.

It is primarily aimed at artists and technical directors who need to integrate real‑world photographs into 3‑D scenes, especially those using Blender. An official Blender add‑on can automatically apply the extracted parameters and optionally set the image as a background, streamlining the workflow. For other programs, users can manually transfer the values by matching the viewport size, field of view, position, orientation, and principal point.

The software emphasizes a straightforward, tutorial‑driven interface and provides source code for further customization. Its cross‑platform availability and free licensing make it a practical utility for anyone requiring accurate camera matching from still images.