If I understand this correctly, the 4:3 ration is for full screen and the 16:9 ration is for wide screen. I'm using TMPG and it also has settings for 525 line with the 4:3 and 16:9 settings. Do you use this when you are going to be viewing the movies through an S-Video connection or does it make any difference at all? I am archiving my old vhs tapes and want to get the best picture possible. Thanks for any help that can be offered.