RMIT3DV is a library of uncompressed stereoscopic 3D high definition video available for free download under a Creative Commons Attribution-ShareAlike License. As part of a research project funded by the Smart Services CRC, the library is a collaboration between RMIT University and Alex and Jono Films in Melbourne, Australia.


About

Film production workflow

The 3D content was natively filmed in 3D using a Panasonic AG-3DA1 3D camera (with integrated twin lens), where the compressed content (AVCHD) was recorded onto the camera’s internal SD cards for preview purposes. The uncompressed content was externally recorded via dual HD-SDI directly onto two Blackmagic HyperDeck Shuttle video recorders housing Intel 520s 240GB SATA3 SSDs (formatted as HFS+). With the uncompressed content captured at 1920 x 1080 10-bit 4:2:2 YUV (25 fps), this resulted in ~8GB/min of video data per channel.

To build a rig/setup to attach the two HyperDeck Shuttles to the Panasonic 3D camera, standard 15mm studio rod supports were used. As shown in the image above, this is a light weight rod support system that employs 15mm rods spaced 60mm apart. Using a sliding release plate to attach to the camera and a 15mm rod bracket system, the rig was built to hold the Hyperdeck Shuttles at the back of the camera in an over-under fashion. Such a rig was designed to provide easy access to the Shuttles’ function buttons for the camera operator, whilst placing the Shuttles at the closest mounting point to the HD-SDI outputs for the left and right video signals.

To preview the 3D content whilst filming, video sequences were viewed on the camera using the compressed SD card footage. Following the on-location filming, non-linear editing and post-production workflow were performed using Final Cut Pro, with edited sequences previewed via Sony Vegas Pro on a Panasonic BT-3DL2550 3D monitor.

3D Filming Considerations

There are several variables to consider when shooting in stereoscopic 3D:

Frame synchronisation: When shooting in 3D, the left and right video signals need to be locked together and 100% frame accurate. Whilst this is done automatically with the compressed video content recorded on the Panasonic AG-3DA1 camera’s internal SD cards, the left and right video signals externally recorded must also be 100% frame accurate. To synchronise the HyperDeck Shuttles, a visual synchronisation approach with a clapper slate was used to accurately match the left and right files in post-production (the HyperDeck Shuttles do not retain timecode information from the camera via the HDSDI outputs).

Convergence point: Due to the fixed 60mm inter-axial distance of the Panasonic AG-3DA1, objects with a convergence between 3-30m were found to produce realistic 3D effects. 3D effects beyond 30m, however, resulted in objects appearing as ‘cardboard cut-outs’. Depending on the size of the final viewing screen, the correct tolerances for positive and negative parallax will vary. To maintain a comfortable level of parallax, the general rule is that the difference between the left and right images should not exceed 3% of the total width of the final viewing screen . As a result, the 3D effect will vary depending on the size of the screen on which the final images are viewed. All footage in the 3D library is designed to be viewed on a 25 inch 3D monitor and viewing on other platforms may cause variance in the final 3D effect.