Filesize query

Hello all,

Am new to camcorders have just purchased a sony dcr-hc19E and am trying to copy the movie footage which has been recorded onto dv tape across to my pc via usb and save it in some format to hard disk.

The problem i am having is im using a streaming program which enables me to save the footage as it streams but the filesize is rediculous....for 10 minuates of footage...the saved AVI is over 3 gigs in size!! Im obviously missing something ... ive watched avis downloaded from the net which last 2 hours and are bearly 600 megs is it the compression? should i be using a program which doesnt stream? Any replies greatly appreciated.