FORCED PERSPECTIVE IN TROLLEY DIORAMAS

From TRAINS.COM, as originally derived from MODEL RAILROADER Magazine

Forced perspective for model railroads
How to make your model cityscape look big
by John Pryke

(Originally published on August 31, 2002)

Looking at scenery from any height, the closest viewscape contains lower buildings. Beyond that in a city might be taller apartment houses, which looked small. Beyond that, maybe a large church, with a tiny steeple. At that distance, vehicles on the streets are only colored dots. From where the viewer might stand, any city looks like (and probably is) a very big city!

If we were to duplicate that city scene exactly in HO, it would take over 30 feet; yet most layouts have only 6" to 18" in depth.. Trying to do that in Mega-Scale
would be even more difficult. There is, however, a method to trick the viewers’ eye into thinking that buildings only a few feet away are far off in the distance, a technique called “forced perspective”.

This is the use of representing objects in the distance to be reduced in size to create the illusion of great distance in a very small space. A simple example is to model the scenery and buildings behind a trolley or railroad car in a smaller scale than the train itself. When the viewer looks over the train at the buildings, they appear to be far away because of their smaller size, even though only a few feet may separate the two. Your eye perceives these decreases in size as increased distance.

How to create forced perspective
When using this technique, it's helpful to create a visual barrier between the railroad and the city. The most common way to do this is to place the distant townscape two or more feet higher than tracks in the foreground. A retaining wall between the two levels works well and follows the prototypical practice of many railroads. Visually, you'll group the tracks in the foreground as one set of objects, all of the same general size, with their depth defined by the physical distance to the retaining wall. Then you'll look up and see the vertically separated cityscape as a second set of objects getting smaller and smaller. The smaller size enhances the illusion of distance through forced perspective.

Within a viewscape, the best way to achieve a sense of distance is to position the different elements of the town (houses, stores, partial buildings, flats, and the backdrop), and then to reduce the physical size of each element the farther it is from the viewer. Using EGRM as an example, the trolley in the foreground (the closest objects to the viewer) are one-and-one-half inch to the foot, or 1/8 actual size. In the townscape, houses just beyond the tracks are also scaled 1½ “ to the foot.. Ideally, partial buildings, if they are immediately behind the complete buildings, would be perhaps one-inch-to-the-foot to make them appear farther away. The next layer back consists of flats, several feet behind the front line of buildings. I find that making flats that are available in O scale makes them look much farther away. Finally, forming a backdrop even further back that reduces the size of the structures even more makes them appear even farther away than the flats. Why? Because to the eye, small size equals distance; the smaller the building the farther away it seems.

Fortunately, the manufacturers of flats and backdrops make their products with forced perspective in mind. Walthers Instant Buildings flats, for example, average 20 to 25 percent smaller than full-size HO. Similarly, the closest buildings in the city backdrops of Walthers, Detail Associates, and other manufacturers are about half HO scale (about 45 percent smaller, on the average), while those in the distance are even smaller.

Relative motion
As viewers look across a set of trains they encounter a visual barrier (the retaining wall) that separates a set of objects of one size (the trains) from a set of decreasing size (buildings, flats, and backdrop). The table at the bottom of the drawing shows the relationship between these objects in terms of percentage of full size, relative detail, and perceived distance.
A second and more subtle way to apply forced perspective is through the relative motion of near and distant structures. If you travel through a city by rail or road, look out the window and take a minute to notice how the buildings appear to move past you. Those closest go by at the speed you are moving. Structures two to three blocks away seem to move much more slowly, while buildings many blocks (or miles) in the distance appear to stand still.

Properly placed, buildings, flats, and a backdrop on you cityscape can achieve the same effect. While the difference in speed is much smaller than in the prototype, it is noticeable, and helps contribute to the sense of distance in the setting.