How to check an edit by the first and last frame of every shot

Last updated 2026-09-10 · 8 min read

What is the short version?

In a fast cut, each shot is on screen for under a second and you cannot judge it by watching. What you can judge is where it starts and where it stops, and a sheet of those two frames per shot reads the whole edit in one look.

1. Go to Vizard Agent with the assembled render.
2. Ask for the entry and exit frame of every shot.
3. Review them in order and name the bad boundaries.

What do you need before you start?

Only the assembled cut. Vizard Agent takes the frames from the render rather than from the sources, which matters because a shot boundary in the finished file is the result of the trim, the transition and the encode together rather than of the trim alone.

• The rendered cut. Not the timeline.
• How many shots there are. It decides the sheet layout.
• What each shot is for. So a weak entry can be judged.
• Whether transitions are used. They blur the boundaries.
• The delivery format. Vertical crops change what is at the edge.

What do you type into Vizard Agent?

Ask Vizard Agent for boundaries rather than for a review in general. A plain request for a contact sheet returns an evenly spaced sample of the video, which is a good way to check framing and composition and a poor way to check the cutting itself.

Prompt

Variants worth knowing:

• "First and last frame of every shot." Not an even sample.
• "In order." So the joins read as a sequence.
• "Fix the boundaries." Scopes the repair.

What does Vizard Agent actually do?

Here is how it went on a real sixty-second beat-synced trailer cut from three separate sources. The entry and exit pass happened after the first full assembly and before anybody sat down to watch the video, which is the order that saves the most time.

1. Assembles the cut to the beat grid.
2. Extracts the first and last frame of every shot in the render.
3. Tiles them in order as a sheet.
4. Reviews the first half of the cut by its joins.
5. Reviews the second half the same way.
6. Pulls a few at higher resolution where something looks off.
7. Fixes the shot boundaries that were wrong.
8. Re-assembles and checks the corrected joins.
9. Only then watches the whole thing for pacing and sync.

Step two is the one that changes what you find. An evenly sampled sheet of a sixty-second cut shows perhaps twenty frames, none of which is a boundary; the entry-exit sheet shows every boundary and nothing else.

Step seven is what keeps this cheap. Almost every fault a boundary sheet reveals is a trim of a few frames rather than a wrong choice of shot, so the repair is a timing change and not a re-edit.

Step nine matters because the two passes catch different things. Frames tell you where the cuts land; watching tells you how the cut feels, and doing the frames first means the watch-through is not spent noticing boundary faults you could have seen on a sheet.

What does the result look like?

A cut whose shots start on their subject and end on their point. Nothing begins mid-blur, nothing lingers a beat past the moment, and the whole thing reads as deliberate rather than as material trimmed to a grid.

Vizard Agent keeps the sheet, so after the fix you compare the same boundaries rather than looking for them again.

When does this not work well?

Boundary frames are a picture check. They say nothing about sound, and they can mislead on shots that are meant to start softly — a deliberate fade in looks identical to a badly chosen entry frame when you see it on its own.

• Deliberate fades. They look like mistakes on a sheet.
• Dissolves and wipes. The boundary is a range, not a frame.
• Audio problems. Invisible in frames entirely.
• Very long shots. The middle matters more than the join.
• Slow, contemplative edits. Fewer joins, less to find.

How do you fix a result that came back wrong?

Name the join, not the shot. Because Vizard Agent has the boundary frames indexed to the cut, "the third join starts too early" is a trim instruction, whereas "shot three is wrong" invites it to go back and choose a different shot.

• "It starts on a blur." The entry moves a few frames later.
• "It hangs on afterwards." The exit comes in.
• "Wrong shot entirely." That is a re-choice, not a trim.
• "The join is a dissolve." Boundaries are ranges there.

How does Vizard Agent compare to doing it yourself?

By hand a fast cut is reviewed by watching it, which shows you the shots and hides the joins — at four cuts a second the eye cannot land on a boundary. Problems get described as "it feels choppy" rather than as three specific trims.

Common questions

Why not just watch it? Because at speed the eye cannot land on a boundary. Vizard Agent shows them.

How many frames is that? Two per shot. Vizard Agent tiles them so it is one sheet.

Does it work on long-form? Yes, though Vizard Agent will note the joins matter less than in a fast cut.

What about dissolves? The boundary is a range. Vizard Agent will show frames either side.

Can it flag the bad ones itself? Vizard Agent will point at the likely ones; the judgement stays yours.

Does it check the sound too? Separately. Ask Vizard Agent for the waveform alongside.

Should I do this before watching? Yes. Running the Vizard Agent pass first leaves the watch-through free for pacing.

Will it re-render everything? Vizard Agent re-renders only after the boundary fixes are agreed.

Can it compare before and after? Yes. Vizard Agent pulls the same boundaries from both.

What about the very first and last shot? Those matter most, and Vizard Agent includes them.

Does it work for vertical crops? Yes, and the crop can change what sits at the edge.

Is a middle-frame sheet useless? No. Vizard Agent uses that one for framing; this one is for cutting.

How long does the pass take? Minutes for Vizard Agent. Far less than a re-edit discovered later.

Why do boundaries go wrong at all? Because a cut placed on a beat lands wherever the beat is, not where the shot resolves.