Miniature sets have been a part of filmmaking since as early as Georges Méliès’s A Trip to the Moon in 1902. They have enabled the creation of some of cinema’s most enduring special effects, from the tornado in The Wizard of Oz to the spaceships of Star Wars and the stunning landscapes of Middle-Earth in The Lord of the Rings trilogy. Despite the increasing use of CGI to produce background imagery, miniatures are still used today in films ranging from Interstellar to The Grand Budapest Hotel. Miniatures are a great way to create realistic-looking effects that are both cheaper than computer-generated effects and have a physical presence that CGI lacks. This post will cover the basics of how to film miniature sets, focusing on camera techniques as opposed to the construction of the sets.
The two images below are of the exact same digital model of a Roman town, with the exception that one is 100 times smaller than the other. Both are shown from roughly the same angle, filling roughly the same amount of the frame. Yet one appears larger than the other. Understanding why that is will be essential for filming miniature sets in such a way as to make them look life-sized. How could the first model be filmed in such a way as to make it look like the second one? This question will be answered by focusing on three aspects of miniature cinematography: depth of field, focal length, and camera angle.
1/100 Scale Digital Model
Full Scale Digital Model
Depth of Field
One of the differences you may notice between the first and second images is that the second image has a wider depth of field. All of the buildings are in focus, unlike in the first image, where some buildings are slightly out of focus. This difference in depth of field is part of why the model looks smaller in the first image. In order to fill the same area of the frame as the “full scale” digital model, the 1/100 scale model must be much closer to the camera, (or the focal length must be increased). By bringing the model closer to the camera, the focal plane must also be closer to the camera to ensure that the model is in focus. The closer the focal plane is to the camera, the shallower the depth of field, and so the 1/100 scale model ends up with a shallower depth of field than the full scale model, which is farther from the camera. The 1/100 scale model’s apparent proximity to the camera gives away its size. To make it look larger, it is necessary to increase the depth of field.
The best way to increase the depth of field when shooting a miniature is to decrease the size of the aperture. The exact f-stop needed to match the depth of field of a miniature to what it would be if filmed at full scale is a function of the miniature’s scale. If the full scale model would require an f-stop of 4, and the miniature were at a 1/25 scale, then the ideal f-stop to use in filming it would be f/100. Unless you are working with miniatures at 1/10 scale or larger, it is probably best to use the narrowest aperture of which your lens is capable. This greatly limits the amount of light reaching the camera’s sensor or film, and this must be made up in other ways. One solution is to increase the amount of light being used to illuminate the miniature. On the filming of Dante’s Peak, the lighting was bright enough to melt the miniatures being filmed. The visual effects cinematographers behind Star Wars: Attack of the Clones had to takes breaks from filming the miniatures as the lights were overheating the camera. If there is no movement involved in the shot, an easier solution is available. Decreasing the camera’s shutter speed and, if possible, frame rate, will increase exposure times and thereby allow filming with a smaller aperture without the need for excessive lighting.
Focal Length
Another thing you may notice about the two models above is that the perspective is different between them. This is due to the use of a longer lens to shoot the 1/100 scale model. It can be tempting while filming miniatures to use a telephoto lens in order to make the miniature appear larger within the frame while also keeping it farther from the lens and thereby increasing the depth of field. However, this also compresses the space, making the model look even smaller. The best thing to do with regard to perspective when filming a miniature is to place the model as close to the camera as possible and film it with a wide lens. This distorts the miniature in a way that makes it appear larger than it actually is. You will notice, however, that bringing the miniature closer to the camera in this way will decrease the depth of field. Hence, there is a balance to be struck between giving a miniature the perspective that will make it appear larger and ensuring that the depth of field is deep enough to sell the effect. A potential issue with having the miniature too close to the camera is that it may be impossible to get the miniature in focus. In this case, you would need to use a longer lens or a macro lens, although the reduction in depth of field from a macro lens might ruin the illusion.
Another important and related question involves filming a miniature that will only take up a small part of the frame. The best thing to do in this case is to film the miniature as large in the frame as possible, without any part of it leaving the frame, and then to adjust the scale of the image in post-production. This allows as much detail to be captured as possible, and it is still possible to make use of a wide lens and perspective to make the miniature look larger.
Camera Angle
Another important aspect of filming a miniature is to make sure that the camera angle is realistic. If, for instance, you were to film a miniature town from a high angle on a tripod, this may be a shot that would be impossible when filming a real town. As such, it would give away the scale of the model. It would be better to position the camera in a place from which the full-sized object could realistically be filmed. For instance, if a full-sized object would normally be filmed from 6 feet off of the ground, a 1/12 scale miniature should be filmed from half a foot off of the ground. Aerial shots of miniatures should be done with movement resembling that of a helicopter or a drone, movement that would be best added in post-production. It is also important to keep in mind the tilt of the camera. If you were filming a miniature mountain, you would want to film it from the same low angle from which you would most likely be filming an actual mountain.
The following video demonstrates the three concepts discussed above and how a deeper depth of field, a wider lens, and a lower camera angle can help to make a miniature appear larger and more realistic.
Conclusion
Miniatures are a useful asset in narrative filmmaking, allowing the extension of sets beyond what can be constructed at a full scale. The key to making a miniature look more realistic is to make it look larger. This can be accomplished using a deeper depth of field, a wider lens, and more realistic camera angles.The techniques discussed here work with all miniatures, although discussion has focused on still models. Miniatures that contain movement require additional techniques beyond these basics, such as filming at a higher frame rate and using a motion control rig. Miniature construction and miniature lighting also require additional techniques. The most important thing to remember when exploring the world of miniature cinematography is to scale everything, whether that be trees, your lens’s aperture, the speed at which objects fall due to gravity, or the size of a light source. The best miniatures, like all good special effects, are illusions that can fool the audience into thinking that a full-sized ship/city/mountain/etc was actually filmed.
References/Further Reading
https://www.theasc.com/magazine/sep02/brave/index.html
http://cinematography.net/edited-pages/Miniature_Depth_Of_Field.htm
http://www.hutchfx.com/fx/HutchFX/web/gallery/fx/dantes/dantes.html
CMA SENIOR SEMINAR 2018 