Learning lab

Perspective simulator

Camera position controls perspective. Focal length controls field of view. Change one, watch the scene, then compare two views.

Your camera view

36 × 24 mm sensor

Near: rock · Middle: tree · Far: mountain · Dashed line: horizon

35 mm · 10.00 m to rock plane · height 1.6 m · sideways 0.0 m · Fixed camera position

Horizontal field of view: 54.4°. Rock-to-mountain projected height ratio: 0.633. Ratio uses full object heights, even when cropped.

What changed?

Try changing focal length first. From a fixed position, it changes framing without changing perspective.

Camera controls

Experiment mode Fixed camera position Matching subject size

Maintain subject size (rock)

The toggle and mode select the same behaviour. In fixed mode, zoom leaves position unchanged; you can still move the camera manually.

Camera distancem

Distance along the viewing axis to the rock’s plane.

Focal lengthmm

24 mm is wide; 200 mm shows a narrower view.

Camera heightm

Height above level ground. The camera does not tilt.

Camera left / rightm

Negative is left; positive is right. Camera direction stays fixed.

Save two views below. Reset restores the camera and mode; saved comparisons stay until you reload the page.

Controls are waiting for JavaScript. If they remain unavailable, the static scene and explanation below still show the starting example.

JavaScript is off. The static view shows a 35 mm lens, 10 m to the rock’s plane and a camera height of 1.6 m. Zooming from this position changes framing, while moving closer increases the rock’s size relative to the mountain.

Compare two viewpoints

Use the same frame size to compare your saved settings. Some objects may be cropped or outside the frame at extreme settings.

Comparison A

No view saved. Choose “Save comparison A” to keep the current view here.

Comparison B

No view saved. Choose “Save comparison B” to keep the current view here.

Begin with a fixed viewpoint

Imagine three equal-sized markers at different distances. The closest appears largest. Zooming from the same position enlarges all three together; moving the camera changes their size relationships.

In this scene the rock, tree and mountain have different real sizes. Compare the rock-to-mountain height ratio as you change focal length, then change camera distance.

What does matching subject size preserve?

The rock’s full projected height, even when it is cropped. A longer focal length moves the camera back; a shorter focal length moves it closer. Camera movement changes the perspective. Moving the distance control manually establishes a new size reference. At the travel limits, matching can no longer be exact.

Why does the horizon stay in the centre?

The camera stays level. Changing height shifts ground features relative to the horizon and changes which part of the foreground is visible. Tilting a real camera would move the horizon within the frame; tilt is not simulated here.

What are the model’s limits?

This original SVG scene uses an ideal rectilinear camera with a 36 × 24 mm sensor. The rock is 1.5 m tall, the tree is 7 m tall and 18 m behind the rock, and the mountain is 45 m tall and 180 m behind it. Objects are flat illustrated planes, so walking sideways changes overlap but does not reveal new surfaces. Lens distortion, focus blur, lighting changes and camera tilt are not simulated. Extreme settings can crop objects completely.

Read how perspective works · Explore focal length vs perspective