A system for providing virtual pan-tilt-zoom, PTZ, video functionality to a plurality of users (60a-60c) over a data network, the system comprising: a plurality of network video cameras (10a-10e) positioned to make a video recording of a real-world target field, or a respective subarea thereof, and output a respective raw video segment onto the data network; a back-end camera calibration unit which is adapted to obtain a relative position and orientation of the respective network video camera (10a-10e) with respect to a three dimensional world space for the target field, and to save the obtained relative position and orientation as metadata for the respective network video camera (10a-10e); a back-end video processing unit, connected to the data network and adapted to receive the respective raw video segments recorded by the network video cameras (10a-10e), to analyze raw video frames of the raw video segments as recorded by the plurality of network video cameras (10a-10e) and to synchronize these frames, wherein the back-end video processing unit is further adapted to store or buffer video contents of the respective raw video segments in a back-end video storage; a back-end video streaming unit adapted to stream the stored or buffered video contents and the saved metadata for the respective network video camera (10a-10e) onto the data network; and a plurality of client devices (50a-50c) for use by the plurality of users (60a-60c), wherein the back-end video processing unit or the back-end video streaming unit is configured to generate a composed video stream from the synchronized frames of the respective raw video segments from the plurality of network video cameras (10a-10e) by putting the synchronized frames one above the other or side by side in one and the same frame of the composed video stream, wherein the back-end video streaming unit is configured to send the composed video stream to the client devices (50a-50c), and wherein each client device (50a-50c) is adapted to: receive the streamed video contents and the metadata; determine a chosen virtual pan-tilt-zoom value; and present, on a display (52a-52c) of the client device, the video contents by projecting directions, or rays, in the three dimensional world space, onto the display (52a-52c) based on the chosen virtual pan-tilt-zoom value and the metadata. a plurality of network video cameras (10a-10e) positioned to make a video recording of a real-world target field, or a respective subarea thereof, and output a respective raw video segment onto the data network; a back-end camera calibration unit which is adapted to obtain a relative position and orientation of the respective network video camera (10a-10e) with respect to a three dimensional world space for the target field, and to save the obtained relative position and orientation as metadata for the respective network video camera (10a-10e); a back-end video processing unit, connected to the data network and adapted to receive the respective raw video segments recorded by the network video cameras (10a-10e), to analyze raw video frames of the raw video segments as recorded by the plurality of network video cameras (10a-10e) and to synchronize these frames, wherein the back-end video processing unit is further adapted to store or buffer video contents of the respective raw video segments in a back-end video storage; a back-end video streaming unit adapted to stream the stored or buffered video contents and the saved metadata for the respective network video camera (10a-10e) onto the data network; and a plurality of client devices (50a-50c) for use by the plurality of users (60a-60c), wherein the back-end video processing unit or the back-end video streaming unit is configured to generate a composed video stream from the synchronized frames of the respective raw video segments from the plurality of network video cameras (10a-10e) by putting the synchronized frames one above the other or side by side in one and the same frame of the composed video stream, wherein the back-end video streaming unit is configured to send the composed video stream to the client devices (50a-50c), and wherein each client device (50a-50c) is adapted to: receive the streamed video contents and the metadata; determine a chosen virtual pan-tilt-zoom value; and present, on a display (52a-52c) of the client device, the video contents by projecting directions, or rays, in the three dimensional world space, onto the display (52a-52c) based on the chosen virtual pan-tilt-zoom value and the metadata. receive the streamed video contents and the metadata; determine a chosen virtual pan-tilt-zoom value; and present, on a display (52a-52c) of the client device, the video contents by projecting directions, or rays, in the three dimensional world space, onto the display (52a-52c) based on the chosen virtual pan-tilt-zoom value and the metadata.