how to modify project without affecting original?

It's also visually easier to treat the snapshot as a backup (and not alter it) because it's named with a date and timestamp. I usually edit the Smart Collection named Projects to hide projects that include the text "snapshot." Then I duplicate it, rename it Projects snapshots, and edit it to only show projects that include the text "snapshots." That way the browser can be de-cluttered when viewing the list of projects.

The edited "clips" you have in the timeline are not really clips. They are just referencing the originals.

They are instructions saying how you would like that clip to look when it is exported. So if you made a clip in the timeline look red the original media clip would be unaffected but the exported version of it would be red.

As the project is simply a set of instructions with no media it will only be a few megabytes in size.

This shows the project files for a 22 minute film called "Keyon"

As you can see, I made a duplicate of it and each one is only 1.1 MB

The media which remains untouched is 8.35 GB

I did one that's 10m long, but I now want another version that's 5m long. I really don't want to duplicate the whole thing.

I would do it like this.

1. Create a new event. →Change the event name to “Test short”.

2. Duplicate the project. →Change the duplicate project name to “Test short”. →Move to a new event. (Manage them separately to avoid opening the original project by mistake.)

3. Start re-editing the project “Test short”. →If you are unsure about the best editing method or want to test it. →Create a snapshot that does not affect the project "Test short" and test to your heart's content.

4. Copy only the good parts of the test results. →Paste it into the project “Test short”. → Delete the snapshot after pasting. (To prevent malfunction)

・Media will not be duplicated. The only increase in capacity is for the new library.👍

・You can create and test snapshots only when necessary, without affecting other projects.👍

As Tom said, you can make a snapshot to ensure that the two versions are completely separate; but what you describe is not normal, anyway. What I believe is happening is that you made the duplicate but then continued editing the original. That is a common mistake. Look at the name above the timeline to make sure you are editing the desired project. Just making a duplicate does not open it in the timeline; the same project remains there. Double click the duplicate to open it.

Making a snapshot does not duplicate any media. There is only one set of media; only the clips are duplicated to create a new set of pointers to the same media. It makes the database fractionally larger.

The snapshot is the project that frozen in time. It should be considered a locked version. Any multicam or compound changes will not propagate through to the same clips in a snapshot.

"The snapshot is the project that frozen in time. It should be considered a locked version."

It's still not clear to me why the snapshot needs to be the frozen one. Isn't it just a copy of the original? And if so, then why can't the original stay frozen and the "snapshot" be my new working copy? I'm not trying to be pedantic; I'm mainly trying to understand if there is literally some difference between the two that I should know about.

That is just the meaning of the word snapshot - like a "photo" of your project at a specific moment in time.

I suppose you could leave the original, and start editing on the snapshot.

It should work as well, but it seems much more logical to do it the way Tom described.

In most cases it will likely make no difference. The only times is fires I think odd of you have clip containers, compounds, multicams, maybe even sync clips. If you work on the snapshot and change a compound or multicam container the original will get changed as well. If you make these changes in the original the snapshot will be unaffected. That’s the way it’s supposed to work. That’s why one is called a snapshot with a time stamp.

I made a few tests, and after creating a snapshot, I was able to do changes on either the original project or the snapshot, and none of the changes affected the other project. So it does appear that the two are completely separate (which I assumed was the case, too). Still, I would follow Tom's advice to treat a snapshot as er... a snapshot, even though it seems to work either way.

Ian R. Brown wrote:

I've asked this before but forgotten the answer . . . what's the difference between creating a snapshot or duplicating a project?

I always duplicate.

If you use compound or multicam clips, a snapshot ensures that they are completely separate.

If you duplicate, they share these.

So if your duplicate includes a compound clip and you make changes to the compound, your original will change too.

If you are using compound clips, changes made to one will affect all instances of that compound clip. You can break that relationship in the new, duplicated project by selecting the compound clip and choosing Clip > Reference New Parent Clip. Depending on how you've built things, another way might be to select the compound in the new, duplicated project and choose Clip > Break Apart Clip Items to essentially un-compound it.

Create compound clips in Final Cut Pro for Mac - Apple Support

Are you using multicam clips or compound clips? Which titles show this problem?

If you want to ensure that nothing propagates to the original project use the Duplicate Project as Snapshot function, and leave the snapshot duplicate untouched and make changes to the original