Hi there,
If I recall, if you have a 16:9 TV and you use (Force) 4:3, I think you will see the movie perfect, but square in the middle of the 16:9 TV.
When you select (Force) 16:9 and the movie is a 4:3, it will stretch the sides to fit the whole 16:9 screen.
Take 2 small movies. 1 in 4:3 and 1 in 16:9 (You will see in the logs).
Then convert both (Force) 4:3
Then convert both (Force) 16:9 and see for yourself what settings you prefer.
I have a normal 4:3 (32") TV and both 4:3 and 16:9 looks ok, but I never saw the end results on a true 16:9 TV
Man, that's a lot of 4:3 and 16:9 numbers on there
I have it on Automatic, it will choose the proper ratio based on the original.
I personally do not like to force it.