My client has an existing DVD that needs updating. It's pure 4:3, both videos and menus. The DVD consists of about eight individual videos.
I have shot a lot of footage in HDV, 16:9, for some brand new videos, as well as to intercut with the existing videos.
The audience is the broad public, and probably a majority have older 4:3 monitors and old DVD players. The older (4:3)videos are mainly addressed to parents, the newer ones to their kids.
I'm planning three different looks:
1. Updated 4:3 videos addressed to older folks: keep strictly to 4:3. When using 16:9 sources, I'll crop to 4:3.
2. Updated 4:3 videos addressed to their kids: output as 4:3, but mix it up with some 16:9 as letterboxed, strictly for the more modern look.
3. Newly-produced videos addressed to teens: use 16:9 anamorphic.
Are there some gotchas to have videos with different aspect ratios on the same DVD?
It is standard practice to use 16:9 menus if you have 16:9 video. Oh, course you don't have to if you don't want to, the disc will play fine with just 4:3 menus.
When you make a 16:9 menu you have options on how it will be displayed on 4:3 TVs, Letterboxed (so the menu will look exactly like video with black bars top and bottom and it scales the buttons overlays to match or Pan and Scan with just center crops the menu. So if you design the menu so all the buttons and important graphics are in the middle this gives you the cleanest look.
The only issues of the mixed aspect ratios are on 16:9 TVs or Computer screens, Menu of different aspect ratios then the video kind of glitch when switching but there is nothing technically wrong with them. If you use 16:9 you eliminate most of this problem.