The camera in Blender is one of the 3 objects (cube and point lamp are the other two) that come by default when we start the blender file.
A camera is an object that defines how our image will be displayed in the render result. If there are no cameras in the scene, nothing will happen when you try to render.
Keep in mind that there must be at least one camera in the scene, and there may be more than one.

How to add a new camera to a scene

To add a new camera to the scene, press SHIFT + A and select camera

Keep in mind that if you add a new camera, it will not be the active camera by default. To set the camera as the active camera, select the camera and go to View ‣ Cameras ‣ Set Active Object as Camera

Frame Camera Bounds – If you want the entire Viewport to be within the camera frame, press Numpad0 then View ‣ Cameras ‣ Frame Camera Bounds

Lock Camera to View – By enabling Lock Camera to View in while in camera view, you can navigate the 3D Viewport as usual, while remaining in the camera view.
To turn on this option, press N to open the sidebar, select the View tab and select Camera to View

Rotate the camera in the blender

Pressing Numpad0 and R (rotate) enters the camera rotation mode. By default, the camera rotates around the Z-axis.
To rotate along the X, Y or Z axis, you need to press R and then X, Y or Z twice. (The first time you select the global, the second the local axis).
For example, try R + XX

Focal Length

Focal length is the distance between the center of the lens and the focus.
By increasing the focal length value, you get the impression of focusing the camera on a distant object, with a lower value you capture a wider frame.
Example: In interior scenes, I usually use a focal length value of 18 or 20 (if I want to capture the whole room) to about 50, if I want to focus on some object on the table such as a vase, fruit and the like.

Depth of Field

With the Depth of Field option, you can set which objects or part of the scene will be in focus, while the rest of the scene will be blurred.
You can set the focus distance value or simply select the object to be in focus. Eg. you can add an empty object and place it in place in the scene you want to focus on.
F-Stop ratio that defines the amount of blurring. Lower values give a strong depth of field effect.

Select the camera in Blender, 3 ways

There are three ways to select a camera in a blender.

  1. By pressing Numpad7, we go to the top orthographic view, then select the camera
  2. Press Numpad0 keyboard we go to Camera Perspective. The Camera view shows the current scene as seen from the currently active camera’s view point. Then select the camera line in Camera Perspective.
  3. Select the camera icon on the right, in the “Outliner tab” under “Scene Collection”
  4. Under Rotation, set the X axis to 90 degrees, the Y axis to 0 degrees. Rotate only the Z axis to get the best camera angle.