Thanks for helping! it seems i got a problem explaining the proplem in english..sorry.
1: the overall output size is 1280 x 720. This match the output size of the background picture (the frame) ( though the actual size of all the pictures used is much bigger and scaled down because they are being zoomed out to their 100%) so the outer frame is not the problem. The dimension of the composition stops it 🙂
The inner pictures should not exeed the borders of what you see on the picture when they are being scaled up. And that is what is my problem. It seems that the masking and also the motion tile suggestion is only restricting which parts of the pictures being used…not the border of them in the composition when scaling them up, unless theres something i just do not get.
So when setting the small pictures up in a composition with a smaller dimension and then afterwards import this QT rendering in the 1280 x 720 with the big background picture…i get what i want. But if it could be done in one stroke, in one composition, it would be smarter i think…and i am sure its propably quite simple…theres just something i do not get.
Hope this explain it…i do not know how otherwise to explain it. But thanks for trying helping me 🙂