Hi, how come my video doesn't fit the screen entirely? And what can I do to fix that?

What are the dimensions of your clips and of your project?

If they don’t match you typically end up with black bars on the sides or at the top and bottom. You can, in the Inspector, set Spatial Conform to “Fill” instead of the default “Fit”.

Or it could be that you are seeing black bars when playing full screen on your mac. That is pretty normal because HD or 4K are typically 16:9 and most mac displays are 16:10.

It appears by the above screenshot that your youtube video may 2.5:1, a very wide aspect ratio.

Please post screenshots of the Inspector for your project and your clips.

Here are examples of the information I'm asking for (this is of a 4K clip shot on my iPhone, and then a project I created as 2K). Note that the clip below is 16:9, but the project is 2:1. A 2:1 project playing fullscreen on your mac screen will always have big black bars.

Your project is 2048x1536.

Your clip is 2704x1520.

They have different aspect ratios. The clip is wider. With Spatial Conform set to Fit, it will leave black bars at the top and bottom (even without a letterbox effect).

It is simple geometry. You put a wide rectangle inside a tall one, and scale the wide so that it fits inside the tall rectangle... like the image below (project frame in orange, clip frame in blue):

kingson629 wrote:

Yes, I have the letterbox effect because I want the horizontal bars to create the theatric effect. However, I am asking about the additional vertical bars on the right that makes the video seem smaller.

It is not clear where the edge of the frame is (even though the second image is clearly narrower). Set the player background to checkerboard to distinguish where the frame ends, and where the clip ends (this is done in Preferences->Playback)

Also, when seeing those images it would be useful to know the clip and project size in each case, and the Spatial Conform setting.

Select your project in the browser and open the Inspector (command-4)

Similarly for the clips. Post screenshots.

Luis showed where the clip dimensions are. Check the properties for the project by selecting it in the browser.

The screenshot you gave isn’t from FCP. Where is that? Can that application fit different aspect ratio clips into a variable size window?

That's a non-standard project aspect ratio. I don't know what YT does with it.

Not sure what the problem is. The project fills the Viewer, no bars left and right, only at the top and bottom. Still can't see the dimensions of the media, but it doesn't looks 16:9; it's some other widescreen format. What is it? Did you use the format in iMovie? Does YouTube support this widescreen format?