Scale model suspended on invisible wire in front of camera — creates depth without building full sets. Classic in-camera trick before CGI.
You need a giant city in the background, but only have a small set in the foreground? Then build a miniature model — take a building a few centimeters in size made of plastic, wood, or foam, hang it on a thin nylon thread in front of the camera, and adjust the depth of field so that it blurs into the out-of-focus background. Voila, the depth illusion is complete. This is the hanging miniature — one of the oldest and most reliable in-camera tricks before CGI took over the industry.
The fascination lies in its simplicity: While your actor performs on the foreground set, the scale model floats three to five meters behind him (or off to the side out of the camera's view). The further away it is, the smaller it can be — perspective makes it work. The trick only works if the lighting of the model matches the background lighting and the thread is guaranteed not to enter the frame. We're talking about extreme precision here: the thread must be dark gray or black, as thin as fishing line, and if necessary, later removed in post-production — formerly mechanically, now digitally. The advantage over matte paintings or other analog techniques? You see parallax, you see a real shift in perspective when the camera pans. This creates credibility.
Practically, you need a stable rigging frame behind the main set, precision mounting points, and a focus puller who keeps the focus constant during movements — because if the model is in focus, it's immediately recognized as a miniature. This belongs to the defocus composite family. Most modern productions no longer use this technique, but we still see it in science fiction and fantasy — some DPs swear by it because the uncompressed depth effect is simply impossible to fake.
A classic example from the analog era: city aerial shots, where miniature skyscrapers were planted in the background, hanging, while the camera and actors moved. This makes the scene appear spatial without having to build an entire city model. Today, we often combine it in a hybrid way — a miniature in front of the camera, a screen or a matte behind it, or we use it as a reference for subsequent digital compositing.