disk space error - final cut express 4
I'm new to final cut express. I color corrected a 60 minute video clip and attempted to export the sequence to Quicktime. It got about 80% complete and stopped due to out of disk space error. I have about 16 GB of remaining internal hard drive space on my macbook pro. I just received the software last night, so I do not yet understand scratch disk setup, etc. Is there a preference I should change or should I export to an external hard drive? I'm attempting to
import the final clip into imovie and idvd.