Scale Models & Miniatures

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General principle of operation
Scale models and miniatures are generally used for a simple reason; using the real thing is impractical. This may be because it doesn’t or can’t exist, that it will be damaged or that the shot is just too dangerous or not possible any other way.

Models can allow you to show better detail than is possible with real objects and can reduce budget and location requirements. They also allow interaction of objects and actors that cannot be achieved in reality and enables you to keep the action in-camera allowing the director to actually see what is filmed. In addition to this it allows the apparent depth of field to be manipulated.

A level of repeated action, dynamism and intimacy can be achieved using motion control and miniatures that is just not possible with a full size environment.

These techniques can be broken down into a number of distinct areas, but in all cases you are tricking the viewer into believing something that is not real, if the illusion doesn’t work, the shot won’t work.

Foreground miniatures
A small-scale set or model is built and positioned between the camera and the principle action in such a way that the two appear to be one seamless landscape or set. This enables you to introduce objects or action that would either not be possible or is much more cost effective if done as a model. Examples of this would be a hovering flying saucer with an actor looking up at it, or a burning building façade placed in front of the real building leaving it untouched.

Background miniatures
These can be used in a similar way to foreground miniatures in that they allow elements to be introduced that cannot be there for one reason or another; but in these instances they will be placed behind the principle action. It is important to remember that although they are miniatures they may well be large objects in their own right. An example of this would be an actor standing in front of a mountain range, where the mountains are models.

Scale models
These may be used for forced perspective shots or simply to make an object appear larger than it is in reality. Alternatively, it may be possible to make modeled objects more attractive or show a higher level of detail than the real ones. It also means that certain problems with depth of field are less likely to occur.

Computer models and post production
In many ways these constructions and techniques can be used as an alternative to physical models or real effects. Ultimately the choice of whether to go one way or the other, must rest upon factors particular to the job.

Computer generation and post-production techniques are very powerful tools, especially when used in conjunction with physical models, but it must be remembered that they are not a panacea and will not work in every situation. Many headaches, heartaches and budgets have been saved by a little careful discussion with the model and effects crew at an early stage. Not everything is best done, or even can be done, in post.

Blue/green screen
A technique called “colour separation overlay” or more colloquially ‘blue screen’ is often used with the techniques outlined above as well as with actors. Simplistically a model or actor is filmed against a flat matte background colour, usually a particular shade of blue or green. A computer is then used to remove all of a particular colour from the shot, leaving only the models or actors, these are then overlaid onto another piece of film.

First considerations
Are models and miniatures the way to go and what are the various ways to set up the shot? There may be several.

Many shots are simple to set up, present few difficulties and do not need specialist crews. Others can be technically very challenging and require a great deal of preparatory work to ensure everyone understands what is required and how it will be achieved. Decide where your job is likely to fall between these extremes and find a DOP, gaffer and model crew that have the experience required.

Decide on your camera speed, when filming models it often helps to use higher speeds. Visually this will give the models and sets more ‘body’ and ‘weight’, not exactly technical terms but it helps everything to look real and feel right. It will have knock on effects regarding camera and lighting requirements.

Budget expectations
Often models and miniatures are used as a means of saving money when compared with a full size shoot. It allows destructive effects to take place with lower damage and set-up costs plus a lower level of risk. Filming on location may be reduced or eliminated and similarly post production costs may also be reduced.

On larger shoots, the model and miniature shoot can be undertaken by a second unit, with the attendant cost savings.

If high-speed camera equipment or higher levels of lighting are required extra costs will incurred, as will be the case if expert DOPs or other crew are used.

Questions to ask
Can I see your show reel?
How do you see this job being set up and at what scale?
What are the advantages and disadvantages of using different scales? – There is always a
trade off.
Are there pitfalls you can foresee?
Can any areas of the models have a lower level of detail or can we work at a scale where
ready-made components are suitable?
How will the smoke/water/fire etc we are using work with the models?

Problems to watch out for and things to do
- Talk to the pivotal members of your crew and be sure that you are comfortable they will provide a good job.
- The size of physical properties cannot be altered, so when models interact with each other or with natural phenomena or substances, there may be problems visually making the shot work.
- In a nutshell, water always behaves like water, smoke like smoke etc, whatever the size of the models they are next to. So if you want a realistic plane crash into the sea, you will not achieve it if the model is 1 meter long because the water will look totally wrong. If the plane is say 15 meters long, then the shot may work well. This caution applies to integrating models and miniatures with anything involving movement or natural phenomena: water, wind, smoke, fire,
explosions, gravity and other objects. You can usually push things to 1/4 scale but seldom any smaller.
- If you are using a higher film speed, be aware of how natural phenomena such as fire and water look when run back at normal speed. Higher lighting levels and specialist operators may be required.
- Parallax problems can make moving shots with miniatures very difficult; this is best explained by the following example. When you look at a distant mountain and a tree positioned a little nearer, as you move from side to side the relationship between the mountain and the tree hardly changes. The tree obscures the same bit of mountain whether you are a step to either the left or right. If you model this arrangement it can look perfect, but as soon as the camera moves, the viewer will see the distances are much shorter in reality than they appear, and the illusion is lost.
- When using blue or green screen, be careful of reflections and light washes from the background colour, so light it carefully and avoid reflective surfaces or fringing may occur. Similar colours on the model and the background may also cause problems as the computer doing the cropping cannot differentiate between the two.

Know the jargon
Back projection An image is projected onto the back of a translucent object and filmed from the front,
often used for putting action into windows in model buildings
Background The area in front of the camera, but behind the principle action
Beam splitters A device that allows the camera to film in two directions at once; a half mirrored
sheet of glass
Body and weight Can’t think of a better way of saying it. It is a just a an overall feeling of ‘rightness’
and solidity
Blue/green screen When an element is shot against a single background colour that is then taken away
using post production, allowing the element to be inserted onto another negative
CG/Computer Using computers to create sets, models, effects etc that are then used in place of
their real counterparts
Chroma key The paint colours used for blue/green screen
Colour separation overlay Posh name for blue/green screen, also known as CSO
Depth of field “The width of the plane of focus”. With every lens there is a band where everything
is in focus, further away or closer than this band and things will be out of focus.
The width of this band is the depth of field. Generally the smaller the object you are
filming, the narrower is the band and the more difficult everyone’s job becomes
Flame/Fire/Inferno And other odd names. The standard manipulation computers
Forced perspective The models harness an optical illusion where the details and structure diminish in
size from the front to the back. This alters the natural laws of perspective, causing
distances to appear greater than they are, producing a forced perspective model or
set. The effect is called ‘foreshortening’
Foreground The area in front of the camera, but in front of the principle action
Foreshortening The effect caused by using ‘forced perspective’ models. The natural laws of
perspective are altered, bringing the point of convergence forwards by distorting the
models in a particular way, tricking the viewer into misreading distances
Fringing The line that is often seen around a matted in object-frequently caused by a
lighting problem
Front projection Projecting on to the front of sets – a quick way of applying detail
Glass shot Use of a painted scene in front of the action to extend or alter a set or view in which
action may be taking place
Henry/Infinity Computers of the post production industry
In-camera Having all the elements of a shot visible through the viewfinder and thus recorded
on the negative
Intercut A negative cut to integrate one scene or element into the general run of the film
Locked off The camera is fixed relative to the model allowing some elements to change whilst
everything else remains the same – used in conjunction with multiple passes
Long lens Lens with a long focal length, used to alter the perceived size and relationship of
elements in the shot – very useful
Matched move Matching camera moves at different scales, usually using motion control. It is used
when integrating real and scale model shots – can be very tricky
Matte An area on the negative where a ‘blank’ area is created to allow another element to
be introduced
Miniature A reduced scale model of a object – not necessarily small
Model/set Used interchangeably in this text
Motion blur Introducing blurred elements to infer motion. Done by changing the shutter angle
Motion control Programmable equipment that allows a camera move to be replicated and easily altered
Multiple passes A camera move is repeated when elements have been added or removed, allowing a
scene to be built up section by section – utilises motion control
Overcrank Running the camera at a higher than normal speed
Parallax As described earlier. Parallax effects make camera moves difficult when using fore and background miniatures
Perspective The visual effect of all lines converging to one point, allowing you to infer the size and
distances of objects
Plate shot A shot used as a reference or background for integration in other areas, usually from
a locked off camera
Post/post-production The manipulation by computer of filmed images, to alter, remove or add elements
Principle action The part of the shot that the viewer will be concentrating on
Scalability The ability of an object or set, but more usually a natural phenomena to visually work
at different sizes.
Step cut Specific frames are cut from a negative, producing timelapse effects in a
controlled way.