Fig 1Where to put the phoneS B A switch set-ups · 1 2 3 looks · space to playside-on · 90° · 6.5 m out · lens 2.0 m
Side-on phone · 60 fpsBehind-the-stumps phone
The 33 points Stance tracks; a sight line where a phone locks onWhat each phone sees: its ground, and the frame in the plane of the actionTripods, tapes from the lens to the action, height staffs, a 90° plateWhere each kind of tool wants the phone, for a right-arm bowler over the wicket (mirror it for a left-armer). Body mechanics (Stance): side-on to the bowling arm, square to the pitch (90°), lens roughly level with the release point, far enough back that the whole arm stays in frame from horizontal to release; Stance asks for a semi-side-on, squarish view with the stumps in frame. Film at 60 fps or faster, 120 or 240 if the phone has it: in this model the arm takes 79 ms from horizontal to release, about 5 frames at 60 fps and 19 at 240. An optional second phone behind the bowler (or at mid-off) shows whether the arm swings square to the first. Ball tracking: ball-tracking apps usually want a phone on a tripod behind the bowler's-end stumps, looking down the pitch with the stumps at each end in frame; heights and distances vary, so check your app's own set-up instructions. One phone can't stand in both places, so the two kinds of tool work best together, with two phones. Illustrative: the side-on distance and lens height shown in the readout, i.e. the distance (6.5 m, the least at which this bowler's whole stride, the stumps and the ball fit 90% of a 26 mm-equivalent landscape frame, rounded up), the lens height (this model's release point, 2.0 m), the landscape orientation, the second phone's spot, the ball-tracking phone's spot (about 4 m behind the stumps, 1.3 m high) and the ball's path.
Stance Cricket™Stance Lab · Filming