Advantages of 960 x 540 project settings?

My clips are 1920 x 1080 but my final output is video with 960 x 540.

Does it make sense to use FCP X project settings of Other > 960 x 540 in this case?
(Spatial Conform Type set to “Fit”)

Possible advantages I see are:

- 100% view in the Viewer
- smaller render files
- faster rendering

Am I correct or should I better work with the full 1080p resolution and downsample with the final encoding?

"should I better work with the full 1080p resolution and downsample with the final encoding?"

Yes to that. Work in the original format. Keep everything at the highest resolution. Make your master in the highest format you can. Compress and resize when encoding.

Thank you Tom. So you think the three advantages I've listed above are not worth the trouble.

I mean I wouldn't loose anything. The original media stays in the event folder. If I ever need a full HD version I would simply go back duplicate the project, set it back to full resolution and re-render everything. I've tested it all titles and even color correction shape masks scale accordingly.

-Martin

There is no benefit in editing in a smaller project. If you're confirming to fit every frame of video has to be rendered. If you edit in a project that matches your media nothing has to be rendered except effects. The video fits the viewer regardless. You'll end up with more render files. They might be somewhat smaller but they won't be faster. It's more complex to render everything to a different scale than it is to render to the native size; one more calculation has to be made.

Of course, that makes complete sense when I set the project size to 640 x 480 (I just tried this) there's a render bar over everything. I wouldn't do that and follow your advice immediately.

But I don't see these render bars when switching to a "quarter HD" project.
I may be missing something here but when I have full HD clips and a project size of 960 x 540 (a quarter) there are no render bars over everything in FCP X. It behaves the same as if it where a Full HD project. Render bars only appear when I drop effects or titles.

Sorry for beeing so persistent but it appears to me that in this special case FCP X just drops every other pixel and sees no need for rendering everything.

I'm not seeing what you're seeing. Whenever I place any HD material into a 960x540 project, the project has to render the clip.

You're correct. I don't know why I got the impression that there is no rendering. I did several tests with my MPEG2 footage. I assume because I used just short test clips rendering was so fast that I didn't notice it. But you are definitely right. I will work in the original format and compress and resize when encoding from now on. Thank you.

Optimize that MPEG-2 footage, it can be a PITA to edit with.