Complex sentence: Betacam SP, VHS, and early digital footage was shot in Standard Definition, in 4:3 aspect ratio, whereas the more contemporary format, HD, has a 16:9 aspect ratio, which is more like film.
Split into simpler sentences: Betacam SP, VHS, and early digital footage was shot in Standard Definition (SD), in 4:3 aspect ratio. Next came a higher resolution format, High Definition (HD), with a 16:9 aspect ratio, which is more like film.