I think you have two choices: decide you want everything to look “widescreen” with black bars top and bottom, or else you want everything to be 4:3.
To make everything look “widescreen,” you can try this: go to a shot that is 4:3; open pan/crop; in the preset window, select 16:9 and apply it. However, most likely the preset will not match the bars you find on your existing widescreen shots. If the lines do match up, then right-click on the shot in the timeline, select “copy”, go to each 4:3 shot, right-click, select “paste event attributes.”
If the preset 16:9 bars do not match up with your existing widescreen shots, add two rows of generated black above your video. Mute one of them. With pan/crop, cut the bottom of one so that it matches the black bars of the existing widescreen shots. Un-mute the second line of black and then cut the top of the other so that it too matches the existing widescreen shots. ( Then your 4:3 shots will be cut off top and bottom.) For either solution, if there is critical matter being cut off either at the top or bottom of 4:3 shots, you will need to slide the shots up or down, one by one, to reveal the important parts.
To make everything look 4:3, go to file/properties; make sure under “template” you have slected NTSC DV (720 x 480) or equivalent, NOT a widescreen version. Then go to one of the shots; open pan/crop, right click on the image in pan crop, select “match output aspect.” That will crop the shot to 4:3. Then right-click on the shot in the timeline, select “copy”; go to each of the other widescreen shots, right click, and select “past event attributes.”
Rick Wise
director of photography
Oakland, CA
http://www.RickWiseDP.com
email: Rick@RickWiseDP.com