Video files showing up taking much more space than they need

[AppleFan22]

I recorded a two part show last year, and when looking at the two parts, each one is over 3 GB. The show only lasted for (about) the length of an average film. After cutting these two parts together and adding some minimal titles in iMovie, the total file came to be 12GB! What's going on? I'm supposed to be making a copy of the show for some friends, but the discs can only have around 4.7GB on them.

 

[Fzang]

Wrong forum?

Also, how did you save the movie? Sounds like you up-converted the file format to something that takes heaps of space.

 

[AppleFan22]

Wrong forum?

Also, how did you save the movie? Sounds like you up-converted the file format to something that takes heaps of space.

Sorry, I didn't know where else to put this.
It came straight off the camcorder. It was a AVCHD playlist thing, but then the two parts were saved separately.

 

[Fzang]

Sorry, I didn't know where else to put this.
It came straight off the camcorder. It was a AVCHD playlist thing, but then the two parts were saved separately.

How did you export the files? You should probably choose 1080p/720p compression. Something that makes the computer purr louder than usual. If you simply saved it losslessly into a container it's going to be huge.

 

[AppleFan22]

How did you export the files? You should probably choose 1080p/720p compression. Something that makes the computer purr louder than usual. If you simply saved it losslessly into a container it's going to be huge.

I just clicked File>Save and then saved it. How can I compress it like that?