How to Film Your Golf Swing on a Phone

Two angles, and exactly where to stand for each

Down the line means standing behind the ball, on the target line. The phone goes in line with your hands at address. Jonathan Yarwood, a GOLF Top 100 Teacher, is specific: not the ball line, not your butt line. Stand on the ball line and your body hides the club.

Face on is square to your belt buckle, ninety degrees to the target line, opposite the middle of your stance. Film both if you can.

Phone height: your hands at address

1 m high, 4 m awayPublished lab setup, 240 Hz camera

Most people hold the phone at chest or eye height, which tilts the frame down and changes the apparent angle of everything in it. Yarwood's rule is hand height at address, for both views. Herman Williams, a PGA professional who films swings for lessons, puts it at waist level, near enough the same place.

The lab study below used a tripod 1 metre high, 4 metres away, with a dedicated camera, not a phone. Phone lenses are wide, so you will end up closer.

Frame the whole club, and both feet

Turn the phone sideways. Portrait wastes the sensor on sky and grass. Put your feet and the ball near the bottom edge, with room above your head for the clubhead at the top of the backswing.

Pose tracking places 33 body points, ankles and wrists included, so a clip that cuts off your feet loses the lower half of the measurement. Tap and hold on your body to lock focus, or the phone hunts through your takeaway.

60fps helps, 30fps is usually enough

Tempo is the number frame rate actually affects. Tour Tempo counts frames, and tour swings sit near a 3:1 ratio: 24 frames back and 8 down, or 21 and 7. Divide 21 and 7 by 30 and you get 0.70 seconds up, 0.23 down. Thirty is the rate Tour Tempo gives for a phone.

So the downswing runs about eight frames, and one frame of error costs an eighth of it. 60fps doubles your resolution for free, and two sources below want more: Golf.com asks for 120fps and up, Herman Williams calls 120fps fine on an iPhone. Higher rates cost light, and a clean bright clip beats a dark fast one. Pebble Swing reads tempo from pixel motion, not from counted frames.

One thing a faster frame rate will not necessarily fix: phone sensors read line by line, so a fast shaft can look bent in a still. That is the sensor, not your shaft.

Four things that spoil the measurement

Resting the phone on a golf bag. It leans, it sits too low, and it moves when you swing. A clip on an alignment stick fixes both.

Standing too far back. Herman Williams wants the tightest view that still holds the whole arc of the club. A body a few hundred pixels tall gives joint angles estimated from mush.

Shooting into the sun. Backlight turns you into a silhouette and the tracker loses your arms against a bright sky. Put the sun behind the camera.

Moving the phone between sessions. Next week, set it up in the same spot at the same height. A lot of what looks like a swing change between two videos is the camera moving.