4 The Rostrum Camera
Once upon a time, practically all 2D animation was shot on to film using rostrum cameras. Although you are unlikely to use one nowadays, the principle terms remain in use in software packages such as Toonz and Animo and it helps to think as though you are using a virtual camera.
Here is a very stylised front view of a typical animation rostrum set-up:
The dark blue shape is the camera. It can travel up and down the column in order to create the illusion that the artwork is getting bigger or smaller - in other words to create what is called a track in or out, (also commonly and incorrectly referred to as a zoom). The simplified animation table shown here has just one set of (bottom) pegs - that is, a single pegbar.
In real life, rostrum cameras are complex bits of engineering. In addition to tracking towards and away from the artwork, the table on which the artwork is sitting can move East/West and North/South and can rotate. Artwork can be on separate pegbars and these in turn can be made to move in various ways. A complex camera move can be a nightmare to achieve. The introduction of computers together with stepper motors in the 1970s made life a lot easier for camera operators, but it remained a skilled job.
The situation is somewhat
different in the digital world, but only for the better. You can
continue to think of the virtual rostrum as being like the real
thing, but now each piece of artwork can be on different pegs and
move and spin in any axis and there is no real limit to the number
of pegbars that can be used. Because the pegbars don't exist for
real, they can cross through each other.
The most important change
regarding the camera in the change from the real world to the digital
domain is that the rostrum camera itself can now float off the column
and move freely anywhere in space,
but it always points straight down!
So, just to make it very clear; our virtual camera can move anywhere in space, but it always points straight down at our virtual artwork:
...SO YOU CAN'T
front view of rostrum
side view of rostrum camera
welcome to Flatland!