Still image backplates

Stills are easier and cheaper to shoot than moving image backplates, so if the scene for your backplate contains no movement and you don’t need to move the camera in shot, then a still image backplate is probably your best option.

Look out for movement

Still image backplate scenes can sometimes contain moving elements, so look out for swaying trees or flowing water which can be a giveaway and lead to an unconvincing result. Also consider the final sequence: if the shot is to be cut with footage that contains dramatic background action such as crashing waves or wind blown foliage, then the sequence dynamic will abruptly change and the still image backplate will look out of place.

Tiled backplates

Another advantage of still image backplates is that they can be layered or tiled together to create much larger frames, which can then be moved in CGI. This allows for extremely dynamic camera moves, which would be impossible in the “real world” and is great if you want to achieve an “out of this world” style for your sequence. For example rotating the camera around two fighting creatures.

Tiling is the process of stitching a number of still images together to produce one large canvas. With care, a 180 or even 360 degree panoramic background can be constructed. Layering to create fake parallax is relatively straight forward to do.

An alternative is to shoot with a fisheye lens. This will be projected onto the inside of a cgi sphere to re-create a backplate. It is generally speaking more limited in its use as the image resolution is potentially smaller. Though eventually as digital resolutions get bigger all still backplates will be shot this way. 

Somes rules for still image back plates

Each shot needs to be planned and executed in the same way as a moving backplate, but with some additional information to consider:

• Image resolution should be 10mega pixels or greater.

• Use a tripod for all shots

• Make sure that the still images overlap each other by no less than 15%.

• If any prominent feature moves (such as tree branches) and is included across 2 tiles, shoot a separate image of it to paste over the movement

• Ensure that the Meta/Exif data is stored with the image or image sequences. If not, then record the f-stop and focal length of the lens for each still frame.

Essential information to record for each shot:

• Make and model of camera

• Camera height (distance from ground to the centre of the lens)

• Distance from camera to foreground, mid ground and distant objects.