MODEL CONTROL

In miniature visual effects work usually the maxim “simpler the better” is employed and most miniature ships have been moved across the tank by pulling an underwater rope. Usually  divers are employed to man-handle the ship into position and to stop it before it hits the wall of the tank. Sometimes a ship might be moved during the shot by a hidden diver on the off camera side of the model. Although I’m using the term “diver” here, in 1 meter of water aqualungs aren’t usually required. In fact where i say diver substitute a technician in a wetsuit or waders. The diver needs to be fit as they will spend a long time in the water during shooting and will also need to be pretty strong. Because the models are usually shot at an over-cranked camera speed they need to be moved pretty quickly through the water. The miniatures can have a great deal of mass when ballasted to sit at the correct water level, making them very difficult to stop when moving at speed.

In the past there was two schools of thought in regard to the building and moving of these miniatures. The British system referred to the models having an open bottom, having no buoyancy, not needing any ballast and riding on trolleys on tracks set on the bottom of the tank. This meant that the models were not at the whim of any waves in the tank and rode steadily in all seas. For smaller scales of models this was probably an asset as it precluded any unnatural bobbing up and down, to give away the scale.The American system on the other hand was to build the models as ships, ballasted to float at the correct water line and free to interact with any waves thrown at them. This means a system of ballasting needs to be employed, preferably one which takes place after the model is moved to the tank. The obvious answer is to provide containers that can be filled with water once the model is floated. Sometimes sandbags are placed into the hulls or lead shot. Any batteries used for practical lighting can also figure in the total ballast. Most radio control ship modelers are surprised at the amount of ballast required for their relatively small models to be brought to the waterline,. When the models are 40 feet or more long, you can understand that the issue of ballast needs to be considered very carefully indeed. Most ships are turned by the action of the rudder which is generally at the rear of the vessel. This means that a ship is turned by swinging the stern around at the rear. To get a model ship which is being pulled by a rope attached under the bow to turn accurately requires the pulling of a second rope  attached at the stern to simulate the action of the rudder. It is not uncommon to find aspects of these models operated by an effects man concealed within the model. He may be employed to operate a rudder, pull on running rigging ropes to set sail angles, fire miniature cannon, or actually pilot the thing around the sea. The huge 60 foot oil tanker built by Derek Meddings’ crew for The Spy Who loved me was reportedly operated from within the catamaran like hull. The catamaran layout was to allow the bow to open and swallow a large model nuclear submarine. Wolfgang Peterson mentions on the DVD commentary for Das Boot that originally the largest U-boat model (11.2 meters/37 feet) was controlled by a diver concealed inside, but he became very seasick and subsequently the sub was towed by a boat out of shot.

In more recent years radio control has been employed as it has got more reliable and less prone to interference. A runaway model 6 meters long could do some serious damage both to itself and any one in its way.

Where a shoot takes place on the open ocean, auxiliary boats are used to tow the models on a long submerged cable so they keep out of shot and don’t leave an unnatural wake destroying the scale of the shot. Shooting of any sort is notoriously difficult at sea due to the unpredictable nature of the weather and waves, that and coordinating a camera boat and tow boat and it is for this reason that many Hollywood studios built there own tank facilities. I will have a look at these in another post.

CAMERA, LIGHTING AND LENS

A fundamental factor in making models appear life size and massive is to shoot them at high camera speeds. This results in them being viewed in slow motion when projected. At normal live action speeds, say when an actor is talking, the film moves through the camera exposing 24 frames per second. If you increase the speed by 4 times to 96 frames per second, whatever takes 1 second to film will take 4 seconds to watch, thereby slowing down the action. Without this the miniature ships would bob up and down on the tiny waves in a most unconvincing fashion. This is easily demonstrable if you have a DVD player capable of faster playback speeds. Take any movie model ship scene and play it back from between 3 and 4 times fast forward and you will get an approximation of the actual speed at which the model was moving. Suddenly the true temporal scale is revealed and the enlarging effect is greatly diminished, the model looks smaller, back to the size it really is. There is an old rule of thumb that was used to determine the appropriate frame rate at which to shoot a miniature. Generally the square root of the scale denominator would be calculated and used as a multiplier to set the camera speed. For example a 1/16 scale miniature would be shot at around 96 frames per second, the square root of 16 being 4 and 4 times 24 equals 96. A larger 1/4 scale model would result in a 2 times increase to 48 frames per second. This formula was generally a good place to start and usually some testing would take place to finalise the speed setting. It follows from this that the smaller the scale the faster you need to shoot and eventually you reach the limit of what is physically possible for the camera to achieve. The reliable old work horse, the Mitchell High Speed 35mm Camera,  if well maintained, was capable of speeds of up to 128 frames per second.

Mitchell 35mm rack over camera

Mitchell pin registered movement

Some of the model ship explosions for Tora Tora Tora were filmed with a camera capable of 360 frames per second, that is 15 times normal speed and about as fast as it is technically possible for an “intermittent movement” to shift the 35 mm film through the camera.  There are cameras which can go faster, they generally move the film through the camera continuously, using a rotating prism to scan the image onto the film as it slides past the aperture. Speeds in the thousands of frames per second can be had here coupled to specialised lighting fixtures which synchronise to the high speed and short exposures. Cameras with the afore-mentioned intermittent movement produce a far steadier image as the film is held stationary by some pins whilst the frame is exposed. Once that is done, the pins are withdrawn, the film is slid to the next frame and parked for the pins to be inserted and the next frame exposed again, hence the term intermittent, it’s a start stop process. It takes a fair bit of expensive precision engineering to get a mechanism that can do this start stop process at such high speeds reliably without ripping the sprocket holes in the film or folding the film up inside the camera like a concertina. Many a take has had to be re-staged because of a camera jam. It is not unusual to record destruction sequences with more than one camera  to be sure of getting the shot. A second angle can always be used in the edit anyway. I have had experience of this myself when a model tanker truck I had built (for a Japanese Ultraman TV series in the late 1980’s) for a sequence where it explodes, a one take shot, was only captured by the second camera. The main camera jammed as the truck detonated. On this series we were shooting on 16mm film, a smaller and cheaper for TV format. Because the film is smaller, of less mass and a shorter distance between frames, the cameras are able to run at faster speeds. We used an Arri SR which can get up to 250 frames per second and a  Photosonics Actionmaster capable of 500 frames per second. It was the latter camera which was prone to jamming but the small scale explosions (and there were many on this show) looked absolutely massive at 500 frames per second.

The faster the film is transported through the camera the less time each frame is exposed to light. Higher speed shooting requires more light to get an exposure on the film. In a studio one can add to the number of lights used or use larger and more intense fixtures. One of the explosion model shoots for Ultraman, the lighting for the high speed shooting generated so much heat that the temperature on the model stage was 65 degrees celsius. We used to call the Effects Director of photography Captain Kilowatt, because of the amount of six lights ( a very bright lighting fixture consisting of 6 par bulbs in each box) he used to use. Another shoot involved using a borescope lens to shoot a miniature set at high speed. This lens is like a thin probe, usually used for inspecting into small spaces such as inside a human body for medical reasons. In this case it was used for the massively wide angle, infinite focus effect required for an orange drink commercial. The lens was particularly inefficient at transmitting light, not to mention the 2 times extender it was attached to. This meant that it took an extra 8 stops of light to get an exposure and to this was then added the extra stops of light for the high speed shooting. The hot glue used on the miniature huts to secure the thatched roofing  melted.

Outdoors in sunlight you might think that it would be a simple matter of just opening up the aperture of the lens. Unfortunately this would result in a shorter depth of field, rendering the extreme foreground and possibly the background “soft” or slightly out of focus. Let us examine this scenario, you are to photograph a real ship and a model of that same ship out on the ocean. The real ship in order to get all of it in frame would be some distance away. You would most likely have the lens focused at infinity. The ship, the sky and clouds in the background several kilometers away as well as the waves and the smaller model in the foreground near you, would all be in focus. If  you now photograph  the model so that it takes up the frame in the same way the full size ship did, you would have to be much closer to the model. Your focus setting would have to be adjusted down from infinity resulting in a shallower depth of field, causing some softening of the extreme foreground and background focus. This is another of the tell tale signs of a miniature effect.  There are some amazing shots of model railroad layouts that are of a very small scale, but photographed with a pinhole camera attachment using long exposures that look pretty convincing. This is due to the ability of the pinhole to image sharp focus from the lens to infinity at the cost of low light admittance. The reverse of this effect proves the point, in the many examples of the tilt shift lens photography seen on the web, where real objects like city streets and cars are made to look like tiny toys by throwing the foreground and background out of focus, usually in combination with speeding up the action.

Wide angle lenses are generally preferred over a standard or telephoto lens as they give a twofold benefit. The first is that wide angle lenses tend to exaggerate perspective which helps in making a miniature appear larger. Secondly a wide angle lens generally has a larger depth of field assisting in keeping everything from close to the front of the lens element to the far background in focus. Sometimes a longer lens is called for to simulate what you would use if you were shooting a full size ship from another ship or helicopter and you wanted to get in close.  It also can compress the depth and make a stormy sea look more chaotic and dramatic.

Originally movies were shot for a 1/1.33 format, that is 1 unit high by 1 and 1/3 units wide, not much more rectangular than a square. Widescreen introduced various ratios up to 1/2.66 which is  1 unit  tall by 2 and 2/3’s unit wide. When widescreen came into vogue, it presented problems for miniature photography. Anamorphic widescreen compresses the image horizontally using a special lens so you get a wider view than normal into the same 1.33 frame. There is a cost for this extra bit of glass and that is lower light transmission. As the aperture is opened to compensate, there is a smaller depth of field.  Wider angle lenses are more difficult to make anamorphic so there tends to be only longer focal lengths available. Generally Anamorphic lenses are not able to focus as close as the traditional ” spherical lens” which means you cant get as close to make your tiny model look big enough. Often the model sequences in a film would be shot spherically and optically cropped and squeezed later in an optical printer. Of course this meant throwing away the top and bottom of your film frame in the process, leaving you with less resolution (more grain) than the rest of the film. An example of this is in the movie Sink the Bismarck, one of the all time classic model ship movies. You certainly don’t notice any change in resolution during the model sequences, there’s too much glorious model action going on. Personally I love the look of an old anamorphic lens. There is an attraction in a widescreen composition. The lenses create a very distinctive horizontal flare  (extremely popular as a digital recreation) and because of the lower depth of field give an image that soft creamy separation of subject and background, though admittedly, not good for miniatures.

Howard Lydecker at his best, sinking the Bismarck

Another important aspect of filming is the camera position or point of view.When shooting a miniature, one way to help with realism is to think of the camera and operator as the same scale as the model. If for instance you are shooting a ship leaving the dock, your camera would probably be on a tripod roughly at eye height above the wharf. If the model was 1/24th scale and you shot a 1/24th scale model from the same position it would look like you were either on a cliff looking down or in a very stable helicopter. To achieve a comparable shot the camera would have to be 1/24th of eye height off the ground. Perhaps you do want to have a shot looking down at the ship from the air. To convince an audience that you didn’t just mount a camera on a tripod and shoot a model you would need to introduce a simulation of both the motion and very subtle vibration you get from shooting from a helicopter or aircraft as you would have had to capture a real ship. A simple method of achieving a realistic pulsing vibration is to use a variable speed drill with a bent bolt in the chuck as an offset weight. The drill is strapped to a board attached to the tripod head. The drill trigger is pulsed on and off to produce a subtle cyclic vibration in the resulting footage which looks very much like that taken from a helicopter. Similarly the physics of shooting from a boat or another ship would need to be simulated to produce a realistic effect. The camera can be mounted in a box with a clear window to shoot through and floated on the water surface guided by the operator. This gives the benefit of a natural wave motion and getting the lens down as low as it can go to the surface of the water. The camera-person should always ask themselves how would I get this shot if it were real and then scale down the camera position or camera move to match the miniature.  For realism, the image gathering  process must be simulated as much as the image gathered. The unrealistic camera position or impossibly mobile camera move is another miniature shot giveaway.

To summarise; a  model shot has a better chance of success in the realism stakes if taken at high speed, with enough light to enable a small aperture (t/f-stop), to get a large depth of field so that everything is in focus. Sounds easy enough…

MODEL SCALE – how big are the miniatures?

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.

The 1/5th U-boat from the movie Enigma, fittingly at Bletchly Park.

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.