Exporting and size of animation

In recent lessons, Mr Andrew's taught the class how to export correctly and how to make sure the size of our animation is consistent. These two things are very simple to understand and comprehend, but after he explained this to us, I realised that my first two scenes were of a much smaller size than the rest of my animation but I don't have time to do these scenes again, so I will have to deal with this. The scenes still look good, they are just smaller than the rest of the animation, so when the scenes are all put together, the first bit of the animation will be blurry.