Scale

The 2 images above are a wide to a medium shot of my film. The background is 4K and there’s no problem to scale into the different shots (wide, close-up etc). 

However the animated characters are .mov files and if I was to simply take the composition as a whole and scale in (which would be so easy and great!) -the characters lose a significant amount of quality.

If I parent the characters to the footage they will scale but at the scale they are already at in the wide shot -so for example -a character in image 1 above -the wide -might be at 30%. When I parent to the footage, the character will scale up but stay at 30% so not as good quality.  

What I’ve been doing is scaling everything separately with key frames -for each shot -which takes a long time with all the above characters! There must be a better way -can anyone help?!