How to Sync Multicam Wedding Footage Without PluralEyes, and Why the Back Camera Still Looks Late

Use the sync your editor already has. Premiere Pro, DaVinci Resolve and Final Cut Pro all line angles up by their sound, and Maxon stopped developing PluralEyes in 2023 because, in its words, that is "now standard in most modern video editing tools". What none of them knows is where each camera stood. Sound travels about 2.9 milliseconds a meter, so once a camera 30 meters back is matched to a lav on the officiant, its picture runs 87 ms ahead of the voice: 2 frames at 24 fps. From about 21 meters (68 feet) that passes the European Broadcasting Union's limit for late sound. Move those angles later by the frames in the table below, or sync them on a clap they can see.

The distance arithmetic in this post is ours, from the speed of sound. The tolerances are the European Broadcasting Union's and the International Telecommunication Union's, and what each editor does is from Adobe's, Blackmagic Design's and Apple's own documentation.

PluralEyes is no longer developed, and your editor does what it did

Maxon put PluralEyes into limited maintenance mode on February 1, 2023, gave it a year of support and critical fixes, and says it will not be updated to work with newer host applications. The editors it plugged into now do the job themselves. What each maker's own documentation says, read on November 3, 2026:

• Premiere Pro (Adobe's help now calls it Adobe Premiere): Create Multi-Camera Source Sequence can sync on a chosen audio track, which Adobe says helps when one audio source runs through every clip, and Clip > Synchronize can use an audio track channel as its reference. Clips that do not meet the sync criteria are left outside the Processed Clips bin, so look there before you cut. The same dialog's "Offset Audio by" moves a separately recorded track by up to 100 frames either way; on our reading it moves that recording against every angle at once, so it suits an offset all the cameras share, not one far camera.
• DaVinci Resolve 21: Auto Sync Audio, on a bin, has Waveform in its Synchronize Using selector and lets you choose the channel (Auto, Mix or a specific one); Create Multicam Clip has Sound as an Angle Sync option. Clips it could not sync are reported in a dialog, and Blackmagic suggests retrying those pairs on their own. The manual does not mark these sync features Studio Version Only, as it does Resolve's transcription.
• Final Cut Pro 12.4: Synchronize Clips and New Multicam Clip both have "Use audio for synchronization", and the angle editor can sync one angle to the monitoring angle by waveform. Apple warns that some recordings are not suited to it, and that if no sync point can be found the clips are synced at their starting points, with no error. Check every synced clip.

Each of them matches sound with sound. That is the whole method, and it is why the rest of this post exists.

Three ways to line up angles, and what each one matches

• Sound (waveform sync). The editor slides each clip until its audio matches a reference recording. It is fast and needs nothing on the day except a microphone on every camera. It matches what each microphone heard, so it carries each camera's distance from the sound into the edit.
• Timecode. Every camera and recorder stamps its files with the same running clock, and the editor lines them up by that stamp. Distance never enters, because nothing is matched by ear. It needs every device jammed at the start of the day, and over a long file each device still keeps time with its own crystal, which the post on audio drift measures.
• Something every camera can see. A clap or a flash, lined up by eye: the frame where the hands meet against the first spike of the clap on the clean recording. It is the slowest of the three and the only one that checks the picture directly.

For most wedding teams sound sync is the right default, because it is the only one that needs no extra gear or ritual on the day. The rest of this post is the one correction it needs.

The offset sound sync leaves in

Light reaches a camera effectively at once. Sound in air travels at about 331 meters a second at 0 °C, rising 0.61 meters a second for each degree (HyperPhysics), so about 344 at 20 °C: 2.9 milliseconds a meter, or 0.89 ms a foot. Every camera's own audio is late against its own picture by that much.

Sound sync then matches that late audio to a lav on the officiant, which heard every word with no delay. To make the sounds line up, the editor moves the whole camera clip earlier by the travel time, picture and all. The voice now plays on time, and the picture of the lips that made it runs early by the same amount.

How much early is too much? EBU Recommendation R37 allows sound to arrive at most 60 ms after the picture, end to end, for television. ITU-R BT.1359 puts the point where the average viewer detects late sound at about 125 ms, and its annex recalls film's older standard for placing sound against picture: within half a frame, about 22 ms at 24 fps. A camera uses up that half frame at about 7.5 meters (25 feet) from the sound, EBU R37's 60 ms at about 21 meters (68 feet) and the ITU's 125 ms at about 43 meters (141 feet), before anything else in the chain adds its share. Our arithmetic, at 20 °C:

• 5 m (16 ft): 15 ms, under half a frame at 24 or 30 fps. Leave it.
• 10 m (33 ft): 29 ms, about 1 frame at 24 or 30 fps.
• 15 m (49 ft): 44 ms, 1 frame at 24 fps, 1 at 30.
• 20 m (66 ft): 58 ms, 1 frame at 24 fps, 2 at 30. The edge of EBU R37.
• 30 m (98 ft): 87 ms, 2 frames at 24 fps, 3 at 30.
• 40 m (131 ft): 116 ms, 3 frames at 24 fps, 3 or 4 at 30 (3.5, so check by eye).
• 50 m (164 ft): 146 ms, 3 or 4 frames at 24 fps (3.5), 4 at 30. Past the ITU's detection point.

Temperature barely moves it: a winter ceremony at 0 °C is about 4% slower than a summer one at 20 °C, a fraction of a frame at wedding distances. The frame counts above round to the nearest whole frame, because video moves in whole frames.

Where it shows at a wedding

• The camera at the back of the aisle on a long lens. It is the one that shows the couple's faces close up during the vows, from 20 to 40 meters back in a long church or hall, and close-up speech is where a viewer sees lip sync.
• A balcony, a choir loft or a wide angle at the back of an outdoor ceremony. Measure the straight line to the officiant, not the floor distance.
• Toasts through a PA. The camera usually hears the loudspeaker nearest it far louder than the person speaking, so measure to that speaker. A camera 4 meters from a speaker stack is about 12 ms late however far across the room the toast is given, and needs nothing.
• Not the cameras within about 7.5 meters (25 feet) of the sound, which stay inside half a frame at 24 fps, and not a drone, which usually records no sound and is placed by eye anyway.

How to correct it

• Sync everything by sound as usual, against the clean recording made at the source: the officiant's lav, the couple's, or the board feed.
• For each angle farther than about 7.5 meters (25 feet) from where the sound came from, divide the distance by 14.3 meters (47 feet) at 23.976 fps or 11.5 meters (38 feet) at 29.97 fps. Round to the nearest whole frame.
• Open the multicam clip or synced group and move that angle's video later by that many frames. Leave the clean audio where it is; it is the reference every angle shares.
• Check it on a close-up of a hard consonant ("p", "b", "t") or on the clap, frame by frame.
• Or skip the arithmetic for that angle: sync it on something it can see, the frame where the hands meet against the start of the clap on the clean recording.

A long ceremony can be off at the start for distance and off at the end for drift, and the two add. Correct distance first, then check the last minute of the file the way the drift post describes. Long real-time edits show both most, which is why the ceremony in a doc edit is the place to check.

When sound sync has nothing to match

• A camera recording without sound, or with its microphone off. Leave every camera's microphone on, even ones whose sound you will never use, because sync needs it.
• A camera too far away to hear the voice over the room. Give it a clap it can see, or sync it by hand on a marker.
• A camera that only heard music. Sync it on a moment with speech or a sharp sound and check it holds.

Which recorders to run, and where to put them so that the vows exist twice, is in the wedding video audio post.

A sync checklist for the wedding day

• Before the processional, one clap where every camera can see it and every recorder can hear it. Again before the toasts.
• Note each camera's distance from the officiant, and at the reception from the nearest loudspeaker. Pace it before guests arrive, or read it off the venue's floor plan.
• Start a new file on every device for each part of the day, so no single file runs long enough to drift far.
• Keep every camera's microphone on.
• After syncing, check each far angle on a close-up of speech before you cut a frame.

Where Pixally Prep fits

Pixally Prep does the syncing before you open your editor. For each part of the day it builds a timeline with every camera and audio recorder lined up and stacked, nothing cut, in a project for Premiere Pro, DaVinci Resolve or, on a Mac, Final Cut Pro, and it builds the first cut of each doc edit you choose on top. The first wedding is free, one per person and one per computer, and each one after that is $8.99. Whatever syncs your footage, check the far angles against the table above before you cut. If you are still choosing an editor, Resolve Studio against Premiere covers what each costs.