Different aspect ratios in the same sequence?

Putting SD 4:3 into and HD sequence is always a huge compromise in terms of quality and the composition of the 4:3 shots.

The options are to use the whole 4:3 frame, which obviously leaves black bars right/left.

I have seen people use a graphic background to fill in the sides instead of black, or even use the same shot stretched, defocussed and darkened or treated as a background. (which I think can look ugly but thats purely a matter of taste and depends on the material)

The next option then is to further zoom into the 4:3, losing the top/bottom in order to fill the HD frame.

But given you have already zoomed into the SD just to get it to HD, further size increases are really going to affect the way it looks.

It also compromises the composition of the shots as you have to lose some combination of the top/bottom of the shot.

As I said its all a compromise but you just have to experiment a little depending on your style of programme and the quality of the uprez.

best wishes
Neil
http://www.patience.tv

You're making the assumption that the pixels are square. If you do a little research on anamorphic SD you'll discover that widescreen SD happily lives within a 720x480 canvas.

Look at the pixel aspect column in final cut for your clips and sequences. Your sequence settings will also tell you your aspect ratio.

Two basic rules:
1) NTSC/PAL SD video is rectangular whether it is 4x3 or 16x9.

2) 1280x720 & 1920x1080 are square. Other flavors of HD are most likely square-but it depends on the format.

I wouldn't recommend blowing up SD video in a HD timeline via Final Cut scaling/distort. There is a really good plugin for After Effects called Magic Bullet Instant HD which in my opinion does a really good job of converting SD to HD.