Lens Length toolbar
To open a toolbar...
DollyZoom
Move the camera location and change the lens length at the same time.
Viewport properties, Lens, Length
Set the camera lens length to 17mm.
Viewport properties, Lens, Length
Set the camera lens length to 25mm.
Viewport properties, Lens, Length
Set the camera lens length to 50mm.
Viewport properties, Lens, Length
Set the camera lens length to 100mm.
Viewport properties, Lens, Length
Set the camera lens length to a custom length.