Andy is right. Here in Oz the tech spec requires you to allow for “zoom”.. when the sides are cut off and the image is blown up…on an old analogue TV using 4×3 (with overscan of up to 20%).
It means your ad looks crappy in 16×9, but it leaST it’s LEGAL! Also, clients tend to complain that there’s a lot of empty space in the image..”why is there so much space around?” So i do one version for approval, then apply changes for the actual ad.
-timmy