By S3D Centre, Emily Carr University of Art + Design
To re-iterate: We are researching not only the standalone benefits of higher frame rates in S3D, but also the effect of VARIABLE HFR on aesthetic and immersion in the context of a single narrative.
FIRST THINGS FIRST in regards to the camera:
1. A camera capable of shooting HFR must be used, and one that provides quick switching between recording frame rates and camera timebase. A noticeable delay on camera will discourage the experimentation of HFR on set.
Cameras capable of HFR in genlocked S3D:
Red Epic (up to 120fps 4K, 300+ 2K), Red One (up to 60fps 4K, 120fps 2K), Phantom 65 (4K up to 141fps, 2K up to 169fps), Phantom FLEX (2K up to 1560fps), Arri Alexa (2K up to 120fps), Arri Flex D-21 (2K up to 60fps). Unavailable when we were preparing for our shoot, now the Sony F65 CineAlta has been announced and shoots 4K up to 72fps, and 120fps at 2K.
2. Remember to match the in camera timebase to the recording frame rate. This is an important but easily confused step for HFR projects. A non-matching timebase and frame rate will result in a VariSpeed product, NOT an HFR product. This is of upmost importance to double check, as the genlock device on your camera configuration could cause a slip in sync (resulting in temporal offset) OR reset of timebase.
Our shooting specs:
Rig: Kernercam S3D rig with motorized IA, convergence, and focus on Preston controllers.
Cameras: RED Epic filmed at 4096×2160 resolution at 59.94, 48.95 and 23.98fps timebase/recording frame rate with a shutter angle of 180 degrees.
Why 24, 48, and 60fps?
The use of 24fps in this production –as the SFR– was chosen due to our North American location, and audience familiarity with the frame rate aesthetic.
48fps was chosen because it is simple to double the 24 frame rate, and if it is required in double flash for projection, this could be done easily. Also since The Hobbit was filmed at 48fps, we were curious to see what the aesthetic was like.
60fps was chosen with television in mind. 60fps performs well on 60Hz, 120Hz and 240Hz TVs without compensation in the motion. 60fps is double the frame rate of regular broadcast television at 30fps, so we considered this might make the frame rate easier for testing in a broadcast environment.
Source: S3D Centre, Emily Carr University of Art + Design