Making objects seem bigger with the second camera

I am making a space shooter game that the player constantly moves forward, think it like an infinite runner game but in space.                           
While the player continues to move I spawn stars and planets on random locations and I want them to look gigantic, but I realized making the game objects actually gigantic wasn’t a good idea.                                        
So I searched a bit and found out with the usage of the second camera it is possible to make the gameObjects much bigger than they actually are.


Exactly like in this video: 1


I set up the cameras and layers, I get the logic too, I need to make the second camera closer to the object to make it seem bigger but how I am going to make the camera closer to multiple objects which all of them in different places?                     I failed to figure it out.

You don’t have to, because your scaled camera uses the same orientation as your main camera. So it only looks where the player is looking.

The thing is the author is showing off his work. He doesn’t explain how to do it. If you visit the reddit discussion linked in that video, you can get some clues:

“You put all the GameObjects that you want in the scaled space on a specific layer, and have a separate camera that renders only that specific layer. The scaled camera then mirrors the main camera’s field of view and rotation. The translation gets mirrored as well, but for every 1 unit, the scaled camera moves only 1/scaleFactor. The parallax effect that comes from that gives you the illusion that you’re looking at something much, much bigger than it actually is.”