Question Background size for 2d camera

I'm totally a beginner in game development.
My problem is:
Now I want to make a background for a slide-scrolling game.
Is Using painting software like clip studio to draw an entire picture a practical way?
(players only see part of the entire background)
I'm wondering that what size is the main camera covering. since I don't know how to set the background scale.
Is that possible to change the camera vision?

Thank you!

 

yes its possible, you can zoom in and zoom out

the camera can cover any size you want

 

@Dreampilot

"I'm wondering that what size is the main camera covering. since I don't know how to set the background scale."

It is easiest to model your game world in metric scale. One Unity unit = 1m. So block out your game's level in that scale, then start moving your camera so that you see your environment as you would like to. In case of 2D camera (orthographic) mode, you don't have to "zoom" you simply set the camera Size. And for 3D camera mode, you can set your camera FOV and move it closer or further away. But if you are creating 2D without any parallax, you don't need 3D camera.

"Is Using painting software like clip studio to draw an entire picture a practical way?"

By "entire picture" I guess you mean entire level? You'll need to first define your target screen resolution, which is most likely something only you know. In general it usually isn't realistic to create some large level as one image / unless you are creating some Lo-Fi pixel art thing. If you don't have much content in one level it might be doable, even if you use high display resolution and high resolution textures. Try and see how much stuff you can fit in one 2048x or 4096x size texture. Then you will start to see what kind of resolution is good enough for your sprites and backgrounds.

 

@rarac got it! Thanks!
@eses That's helpful! huge thank!