Okay, here I am.
I attached two screenshots. It’s written in Italian, but I think you can understand. Anyway, I want to capture some videos from my video camera (I haven’t done it yet) and add imported clips. When I created the project, I selected PAL 4:3 (not PAL Widescreen) because this is my videos’ format. I think the project size is 720p, as you can see. Then I imported the clips you see before capturing the videos from my camera. The imported clips are 16:9 widescreen and quite high resolution. I want to deliver a high resolution video, but the resolution of the videos of my camera isn’t as high as that of the clips I imported.

