A bit of confusion sometimes arises with boxes that say 25ft, when actually the developed reels inside the box are 50ft. If you look a little closer, you’ll see it will say ‘Double 8′. The reason being, Regular-8, or double-8, spools of film were 25 feet in length before developing and double width, 16mm to be exact, which derived from Kodak in the early 1930’s trying to find a cheaper alternative to 16mm film to expand their market for the masses. They decided to make the images smaller and fit double the amount of ‘content’ on a 16mm width piece of film, which at the time, 100ft of 16mm film would run about 2mins, where as 25ft of film for 8mm use could run 3mins, so a huge increase in running time and therefore bringing the price down. So as you see in the image below, which is undeveloped film, it’s 16mm wide. The film is run through the camera twice to expose both sides. After developing, the lab would split the film down the middle and spliced it together to yield actual 8mm film as you see today totaling 50ft. Below is a picture of how your film originally looked before developing, holes on both sides and double the width.