zSetCamera creates a separate floating viewport with a two-point perspective camera and a parameter panel that drives the camera live. It does not change any geometry in your scene. It only works on camera parameters.

Quick start

Run zSetCamera.
Optionally pick a ground or slab surface (or just press Enter to skip). The tool casts a ray straight down from the camera position of the source viewport to find the ground Z.
The tool creates a floating window (1600 x 900 by default, in a render display mode) and opens the parameter panel.
Adjust VIEWPORT, CAMERA CONTROL (LENS, POSITION and FRUSTUM SHIFT) and NAMED VIEW. The floating window previews live.
Set confirms and closes the panel (the floating window stays). Cancel discards and closes the floating window.

VIEWPORT

Aspect Ratio: 16:9, 1:1, 4:3, 5:4, 4:5 or Custom.
Width / Height: the render resolution.
Lock Ratio: forced on and disabled unless the ratio is Custom.
Show Grid: shows the rule-of-thirds lines. On by default.

CAMERA CONTROL > LENS

Lens Length (mm): starts at the 35 mm equivalent focal length of the source viewport camera.

CAMERA CONTROL > POSITION

Eye Height: a preset of Custom, Seated (3.75 ft), Standing (5.25 ft, the default), Tall (6.5 ft), Balcony (12 ft) or Bird’s-eye (50 ft).
Camera Height: the camera height, kept in sync both ways with the Eye Height preset.
Camera Dolly / Camera Strafe: move the camera forward and back, or left and right, along its viewing direction.

CAMERA CONTROL > FRUSTUM SHIFT

Vertical Shift / Horizontal Shift: shifts the view frustum up or down and left or right, without re-aiming the camera.

NAMED VIEW

Prefix + Save View: the name is built as prefix_aspect_lens. If the prefix is empty, a timestamp is used.

How the settings work together

Camera Height and the Eye Height preset follow each other both ways. Choosing a preset writes the value into Camera Height. If you type a Camera Height that does not match any preset, the dropdown falls back to Custom.
Width / Height and Aspect Ratio are linked. With the ratio locked, changing Width works out Height. If you change Height by hand while the ratio is not Custom, the dropdown switches to Custom.
Dolly and Strafe cast down again to find the ground Z, so Camera Height always means the height above the ground directly below the current position, which suits uneven ground.
Horizontal Shift needs the lens symmetry constraint to be unlocked first. The tool does this automatically.

Good to know

Set does not create a named view. It only closes the panel and keeps the floating window. To create a named view, press Save View.
Cancel really closes the floating window and discards it.
You can press Enter without picking a ground. The ground Z is then 0.