I am trying to slow down a short (15 second 60fps - filmed in 720p with GoPro HD Hero) clip of me surfing. I am only slowing down around 5 seconds which will then stretch to about 30 seconds slowed down.
Once I do this it works well inside After Effects - everything looks ok.
I then render it using HD settings and quicktime format.
Anyway, the file size then blows out to like 7GB for a 40 second clip? This seems absolutely ridiculous - can someone tell me what I am doing wrong?