The Camera view shows the current scene as seen from the currently active camera's view point.
The Camera view can be used to virtually compose shots and preview how the scene will look when rendered.
The rendered image will contain everything within the dashed line.
参考
Camera Settings for details how camera settings are used for display & rendering.
ヒント
The active camera can be selected while in camera view using the camera frame
(assuming the object isn't hidden).
By default a scene contains one camera. However, a scene can contain more than one camera,
but only one of them will be used at a time.
So you will only need to add a new camera if you are making cuts between them.
See Animating Cameras.
This matches the active camera to a regular (non camera) view,
for a convenient method of placing the camera without having to move the object directly.
By enabling Lock Camera to View in the View panel of the Sidebar region,
while in camera view, you can navigate the 3D Viewport as usual,
while remaining in camera view. Controls are exactly the same as when normally moving in 3D.
To perform these camera moves, the camera must first be selected so transform operations apply to it.
The following actions also assume that you are in camera view.
Having done so, you can now manipulate the camera using the same tools that are used to transform any object:
Roll(ロール)
Press R to enter object rotation mode. The default will be to rotate the camera in its local Z axis
(the axis orthogonal to the camera view), which is the definition of a camera "roll".
垂直Pan(パン) または Pitch(ピッチ)
This is just a rotation along the local X axis. Press R to enter object rotation mode,
then X twice (the first press selects the global axis,
pressing the same letter a second time selects the local axis -- this works with any axis;
see the Axis Locking page).
水平Pan(パン) または Yaw(ヨー)
This corresponds to a rotation around the camera's local Y axis.
Press R, and then Y twice.