As of NUBIGON v6.0.0., cameras are now individual items in the Object List. You can create multiple cameras in the same scene and configure them from the Object Inspector.
An empty scene contains a default camera object named Camera. You cannot delete the default camera. Click 
to create a new camera object.
Select a camera in the Object List and click 
to look through that camera. We call the camera through which we view the scene the active camera. The name of the active camera is shown in the bottom center of the viewport.
Select a camera in the Object List and expand the Object Attributes to configure camera attributes. You can then adjust the following parameters:
Camera Attributes
Type: You can choose between perspective and orthographic camera types.
Focal length: Distance between the lens center and the image sensor, stated in millimeters. Changing the focal length changes the angle of view. The shorter the focal length (e.g., 18 mm), the wider the angle of view.
Orthographic scale: This factor controls the dimension of the scene portion captured from the camera. Changing this value has the effect of zooming in and out of the scene.
Near and far planes are located at two particular distances from the camera position along the camera's view direction. Only the part of the scene between these two planes will appear in the viewport. Scene objects closer to the camera than the near plane or farther from the camera than the far plane will be clipped and not rendered.
Constraints
Target
You can make a camera aim at a specified "target" point.
To set a target point, type the name of an object into the Target box and press ENTER. The camera will then aim at the object's pivot point. To see the pivot point of an object, select the object in the Object List and click 
from the toolbar.
See this article for editing the pivot point of an object.
Alternatively, click 
to choose a target point in the viewport. The chosen target point will be created as an item in the Object List (the green point in the below picture).
Once set, you cannot manually rotate the camera. The camera will always aim at its target point.
Preserve distance
Checking this box will fix the distance between the camera and its target point: any camera movement along the camera's up and right axes will rotate the camera around its target point.
For rotations at fixed angle steps, activate the Rotation step checkbox in Settings Window > Translate/Rotate/Scale 
, and choose your desired rotation step.