Estimate memory card space for photos and video.
Stills and video are sized in completely different ways. Photos are a count multiplied by file size, where a full-frame raw runs 25 to 50 MB. Video is a bitrate over time, and because bitrate is in megabits you divide by eight to reach megabytes — a 100 Mbps codec consumes about 45 GB an hour. The recommended card adds a thirty percent margin for retakes and bracketing.
Stills and video volume
Photo GB = photos x file size MB / 1024; video GB = bitrate Mbps x minutes x 60 / (8 x 1024)
Card sizing
Recommended card = smallest standard capacity at least 1.3 x total requirement
Because it records twenty-four or more frames every second with far less aggressive compression per frame. Twenty minutes at 100 Mbps outweighs several hundred raw stills.
Several smaller cards limit the damage if one fails or is lost, which is standard practice for paid work. A single large card is more convenient but concentrates the risk.