Film your golf swing from two angles: face on and down the line. Face on, set your phone square to your chest. Down the line, set it behind your hands, looking along your target line. Keep it still at hip height, step back until your feet and the club at the top fit in the frame, and record in slow motion with the light behind the phone.
Each angle shows you different moves. Face on, you see your head, your hip shift and your finish. Down the line, you see your forward bend, your seat and your downswing path. Set up the same way every time and this week's clip lines up with next month's.
Lead and trail in this guide mean your target side and your back side: left and right if you swing right-handed.
Set up face on, square to your chest
- Take your address with a 7-iron. Lay a second club on the ground from the middle of your stance straight out, at a right angle to your target line.
- Walk out along that club and set the phone on the same line, straight across from your chest.
- Put the lens at hip height and keep the phone level, facing you square.
- Step back along the line until your whole swing fits in the frame.
Square matters because your head and hips move along the target line. With the phone straight across from your chest, those moves cross the screen at full size. Set the phone off to one side and part of each move heads toward the lens or away from it, so your hip shift looks shorter than it really was.
From here you read your head at the top and at impact, your trail hip at the top, your hip shift at impact and your finish over your lead foot. You also see your ball position at address and your hands at impact: the shaft leaning toward the target, or the clubhead flipping past your hands.
Set up down the line, behind your hands
- Lay a club on the ground just past the ball, pointing at your target.
- Take your address and drop a tee straight below your hands.
- Walk straight back from that tee, parallel to the club, and set the phone there with the lens at hip height.
- Aim the phone along your target line, level, with your whole body in the frame.
Stay on the line through your hands. Slide the phone a foot to either side and the same swing draws a different path on screen, so clips from different days stop matching.
From here you read your forward bend at address, at the top and at impact, how far your seat moves toward the ball, and whether your downswing comes from the inside or over the top. TPI diagnoses over the top from this same target line view, by tracing the shaft plane at address and watching the club on the way down.
Set the height, the distance and a steady stand
Put the lens at hip height for both angles, and use the same height every time. Keep the phone level. A tilted picture skews every angle and line you read, and it mixes up and down movement with movement toward the ball.
Step back until your feet and the clubhead at the top both sit inside the frame with room to spare. Make one practice swing with the longest club you plan to film and check the playback before you hit. Stay on the 1x lens. The 0.5x wide lens stretches the edges of the picture, and the edges hold your club at the top and at the finish.
Keep the phone still. A tripod with a phone clamp works best. Without one, clip the phone to your golf bag or to an alignment stick pushed into the turf. Skip handheld clips: a friend's hand drifts, and the drift looks like your body moving. Push two tees into the ground where the stand sits, so next week's clip matches this one.
Record in slow motion, in good light
Switch to slow motion. TPI's Phil Cheetham asks for 120 or 240 frames per second, with 120 as the minimum, and a shutter of 1/1000 of a second or faster. The reason fits in one number: TPI's 3D ranges put the downswing at 233 to 296 milliseconds. At a normal 30 frames per second, a downswing in that range fits in 7 to 9 frames. At 240, it spans 56 to 71.
Even 240 frames per second usually misses the strike itself. The ball stays on the clubface for about half a millisecond, and Cheetham notes that you'd need at least 2,000 frames per second to catch impact every time. Read the frames on either side of impact.
On an iPhone, you get 1080 HD at 240 frames per second in Slo-mo from the back camera by default, and you can change it in Settings, then Camera, then Record Slo-mo, per Apple's iPhone guide. On a Pixel, switch the camera to Slow motion and choose 1/8x for very fast motion, per Google's Pixel help.
Light your swing from the front. Put the sun behind the phone or off to its side. With the sun behind you, your body becomes a dark outline and the club disappears against the sky. Slow motion needs light too: at 240 frames per second, each frame gets 1/240 of a second at most, so in dim light your phone can't reach a fast shutter and the club smears. In daylight, you get a fast shutter without touching a setting. Under range lights at night, stand where the light hits your front.
Read your checkpoints from each angle
Each checkpoint has a line, and crossing it means a fault. Read your numbers against these tour benchmarks:
| Camera, moment | What you check | Fault line |
|---|---|---|
| Face on, top | Head away from the target, from its address spot | More than 4 in: a sway |
| Face on, top | Trail hip outside the trail foot | More than 1 in: a hip slide |
| Face on, impact | Hips toward the target, from address | Under 1.5 in: hanging back. Over 11 in: the hips slide past |
| Face on, impact | Head toward the target | More than 5 in: the head gets ahead of the ball |
| Face on, finish | Hips behind the lead foot | More than 7 in: falling back |
| Down the line, top | Forward bend lost | More than 8°: standing up |
| Down the line, impact | Forward bend lost, seat toward the ball | More than 7°, or the seat over 2.5 in with 3° or more lost: early extension |
On our bench of 21 test clips, tour pros and a skilled amateur shifted their hips 3.8 to 8.2 inches toward the target at impact, moved the head back 0.7 to 3.5 inches at the top, and kept their forward bend within 5 degrees. An 18 handicap lost 9 degrees of forward bend through impact. TPI defines early extension as your lower body thrusting toward the ball in the downswing, which is why you catch it from down the line.
Each fault has its own page: sway, hanging back and early extension. If your misses come out heavy, start with Stop hitting fat golf shots.
In Scratchmaxx, you record face on or down the line, or import a clip you already shot. You get each number in inches, scaled from your height, or in degrees. Put several swings in one clip and you get a read of each one on its own, then start with your costliest fault and a drill for it. In your swing read, you also see your tempo. Aim for a backswing about three times as long as your downswing: the pros in TPI's 3D database come in at 3.2.
Measure your swing with Scratchmaxx.
Avoid five setup mistakes
- Set the phone on a stand. Any drift in the frame looks like body movement.
- Step back. Stand too close and the club leaves the frame at the top or the finish, and you lose the top checkpoint.
- Level the horizon. Switch on your camera grid and line it up with a flagstick or a building edge.
- Stay on your lines. Face on, square to your chest. Down the line, on the line through your hands. A foot off either line changes what you see.
- Keep the sun behind the phone. Backlight hides your body in shadow and the club against the sky.
Run the 5-minute checklist
- Pick a spot with the sun behind the phone.
- Lay one club along your target line and one from the middle of your stance toward the face on spot.
- Face on: phone straight across from your chest, lens at hip height, level.
- Down the line: tee under your hands, phone straight back from it, lens at hip height, aimed along the target line.
- Make one practice swing per angle and check that your feet and the clubhead at the top stay in the frame.
- Switch on slow motion, start recording, then step in. Hit three balls per angle with the same club.
- Leave the phone alone between swings, and mark its spot with tees for next time.
