As mentioned in the About this website introduction, Water droplets do not scale and the water droplet size is the single most tell tale sign of a miniature effect, consequently the size of the model has a very great bearing on the realism of the final shot. The bigger the scale of the model the smaller this droplet will appear to be and therefore more realistic. Miniature ships for visual effects photography therefore have been traditionally the largest single miniatures built, a product of both the dimensions of a full size ship and the model scales generally thought to produce the best miniature photography results. Traditionally 3/4 inch to the foot or 1/16 scale was the smallest scale at which it was thought practical for believable miniature ship photography in water. Budget considerations and subject matter can vary the selection of scale from one inch to the foot or 1/12 scale, down to 1/2 inch to the foot, 1/24 scale. There are some notable examples of exceptions to these choices of scale. Due to a number of factors, the miniature replica of the Queen Mary for the Poseidon Adventure of 1972 was built at the relatively small 1/48 scale or 1/4 inch to the foot. This still resulted in a ship model of 21′,6″ ( 6.5m) length. Many radio control enthusiasts and the ship hobby plans they build from are at this scale, though very few would approach these prodigious dimensions. By contrast the miniatures for Tora Tora Tora (1969) averaged 40 feet (12.2m) in length with the Japanese ships built at 1/24 and the American ships at 1/16 scale. It was not for any national pride reasons that the American ships were built to a larger scale than their Japanese counterparts, it was simply that the American ships had to be largely destroyed and it was considered that the miniature explosions would look better at the larger scale.
Submarines and sailing ship models in more recent films, particularly where they have been shot out on a real sea, have been made to 1/5 and 1/6 scale, an example being the U-boat model made for the movie Enigma. That model now resides as an exhibit at Bletchly Park, the WW2 centre for breaking the German Enigma code. With even smaller subjects such as ocean going yachts 1/4 scale has been employed.
It is hard to get a sense of the size of some of these models when you read a figure like this in a book or on a web page. Run a tape measure out at home like I did and see just how massive a “small” 21′,6″ or 6.5 metre model really is. Not something you could easily put into the average hatchback and take down to the local pond.
The size and scale of a model has a direct bearing on the effort and artistry required to produce a realistic effect. The obvious conclusion is that as the scale reduces from 1/1 the more difficult it is to convincingly mimic full size. A extremely large model shot outdoors in real sunlight has the most chance of success but both the cost of building and the practicality of manipulating such a model are factors which keep this in balance. After all the choice of using a miniature shot in the first place is because it is too expensive, too impractical, or too dangerous to achieve for real.