Dolly

A dolly moves the camera itself, so the relation between near things and far things changes as it goes. That change is parallax, and it is the one thing in a moving shot that the eye reads as travel rather than as a picture being resized.

It also gives a scene a point of view that walks. The audience stops looking at a frame and starts moving through a space, which is why a dolly is the default move for entering a room or leaving one.

The camera sits on a wheeled platform, on rubber tyres for a smooth floor or on rails laid for the shot. A grip pushes it, and the speed comes from the length of the move set against the length of the take.

Parallax is the product. Something close to the lens crosses the frame quickly and something far away barely shifts. Put an object in the near foreground, a doorframe, a chair back, the shoulder of somebody standing, and the move has an edge to measure itself against.

Speed carries meaning on its own. A slow dolly reads as pressure. A fast one reads as urgency. Neither is a default, so the prompt has to say which one it wants.

Use it to enter or leave a space, to carry a thought across a room, and any time the geometry of a place is part of the scene.

Skip it when the frame has no depth. A dolly across a flat wall gives you a sliding wall, and the move spends the length of the shot on nothing.

A zoom changes the focal length and leaves the camera where it is, so everything in frame scales together and nothing overtakes anything else. A dolly moves the body, so the near plane and the far plane travel at different rates.

The test is the foreground. Watch one object near the lens. If it crosses the frame faster than the background, the camera travelled. If everything grows at the same rate, it was a zoom.

The usual result is a zoom wearing a dolly's name. The frame closes in, the background scales with it, and the shot reads as a crop. Write parallax into the prompt and name a near object that has to pass through frame.

The second result is a still camera with a moving subject, which a model gives you readily because it is the easier picture to make. Say the camera travels, and say what it travels past.