How can I mix a video in Full HD (1920 x 1080) with a vid in HD (1280 x 720) I'm trying to export a video of Premiere CS6 and I am having some problems... My two cameras record in different size, and when I'm working with the clips on the program, everything looks great and works well, but when I export them, the clips that were for the Full HD camera doesn't looks like in the programe, they are kind of ampliated.

If someone understands what I'm saying and can help me, I would be grateful!
Thanks!!
At Premier Pro, see Effect control tab on the top left, select scale. Then you adjust the percentage of size of video match your sequences setting.
If your sequence setting are HD 1280×720 then you 0r FHD 1920×1080p videos all need to scale smaller. Final of your video will be 1280×720. Same to if your sequence setting in FHD then your HD video need to be scale up enlargement, it will blurer the videos, need to add smart sharpen at Effect tab below left to an adjustment layer .