ReplayR for golf instructors

Q: What buffer length works best for golf?

A full swing from address to follow-through is about 2 seconds, so an 8 second buffer captures the set-up, the swing, and the finish with margin. The 45 second free buffer is more than enough; you save the swing the moment the ball is struck and the whole motion is on the phone.

Q: Should I film down-the-line or face-on?

Both, and ideally one at a time. Down-the-line (camera behind the player on the target line, at hand height) shows swing plane, club path, and posture. Face-on (camera square to the player's chest) shows weight shift, sway, and the low point. Run one angle per session or switch the tripod between them.

Q: Do I need a high frame rate for swing video?

The swing itself is fast, so 60fps is the practical minimum for clean slow motion, and 120fps or 240fps lets you crawl through impact frame by frame. ReplayR records at your phone's chosen frame rate and plays saved clips back in adjustable slow motion so you can study the moment of contact.

By Erwan Alliaume

TL;DR. A swing is about 2 seconds from address to finish, and the moment that matters, impact, lasts a hundredth of that. Mount the phone down-the-line or face-on, keep an 8 second buffer, and save the swing the instant the ball goes. Walk it to the student and scrub through impact in slow motion before the next ball. On-device only: no cloud, no student footage leaving the bay.

Why golf instructors pick ReplayR

Save the swing, not the range session

A rolling buffer holds the last few seconds in memory and writes to disk only when you save. You keep the swings worth reviewing, not a 90 minute file of a student rummaging in their bag between shots.

Slow motion through impact

Saved clips play back at adjustable slow motion, so you can crawl through the downswing and the moment of contact. Film at 60fps or higher and the slow-mo stays smooth enough to read club face and shaft lean.

Review at the bay, between balls

Save, walk the phone to the student, show the swing in a few seconds. The cue lands while the feel of the swing is still fresh, which is when a change actually sticks for the next ball.

No cloud, footage stays yours

Clips stay on the device. That suits instructors who would rather not put paying students' swings in a third-party account, and ranges with their own camera rules.

Camera angles

Down-the-line

Mount: behind the player on the target line, lens at hand height.
Shows: swing plane, club path, posture, and spine angle.
Buffer: 8 s covers address to follow-through.
Frame rate: 60 fps or higher for smooth slow-mo into impact.

Face-on

Mount: square to the player's chest, a club-length or two away.
Shows: weight shift, sway and slide, low point, and head movement.
Buffer: 8 s; save on contact.
Frame rate: 120 fps if you want to study the strike frame by frame.

Putting / short game

Mount: down the putting line or face-on to the stroke, low to the ground.
Shows: stroke path, face angle at impact, and tempo.
Buffer: 8 s is ample for a putting stroke.
Frame rate: 60 fps; the stroke is slower than a full swing.

Indoor bay / simulator

Mount: down-the-line clear of the screen and the ball flight.
Light: keep frame rate at 60 fps if the bay is dim, since high fps needs more light.
Buffer: 8 s; save on contact.
Note: works fully offline, no range Wi-Fi needed.

A typical lesson

Set the tripod down-the-line, lens at hand height.
App opens, recording starts, screen sleeps, a power bank covers a full day of lessons.
Student swings. You watch the live ball flight, not a screen.
Tap the watch as the ball goes. 8 s saved.
Walk over, scrub through impact in slow motion, give one swing thought.
Switch the tripod to face-on for the next block if you want a second angle.
End of lesson: a folder of the student's best and worst swings, ready to compare.

FAQ

What buffer length works best for golf?

A swing is about 2 s from address to finish, so an 8 s buffer captures set-up, swing, and finish with margin. The 45 s free buffer is more than enough; save the moment the ball is struck.

Should I film down-the-line or face-on?

Both, one at a time. Down-the-line shows plane, path, and posture. Face-on shows weight shift, sway, and low point. Switch the tripod between them or run one angle per block.

Do I need a high frame rate for swing video?

60 fps is the practical minimum for clean slow motion; 120 or 240 fps lets you crawl through impact. ReplayR records at your phone's chosen frame rate and plays clips back in adjustable slow motion.

Is footage safe for junior students?

Yes, ReplayR is on-device only. Nothing uploads. The instructor controls who sees the phone and when clips are deleted.

How ReplayR compares for golf coaching

Criterion	ReplayR	Coach's Eye	Dartfish Express
Price	Pay once, keep forever	$9.99/month	$12.99/month
Works offline at the range	✓ Fully offline	✗ Requires internet	✗ Requires internet
Instant replay (no save needed)	✓ Rolling buffer	✗ Must save first	✗ Must save first
Slow-motion playback	✓ Included	✓ Included	✓ Included
Line & angle annotation	✗ Not included	✓ Drawing tools	✓ Drawing tools