Make a plane fit the screen

Hello everyone first of all english is not my first language but I will try to explain as best as I can.

I’m trying to make the camera display an image of an object when the player presses a key to check on it. Similar to the classic resident evil games, Imagine you are walking around in third person view and suddenly you want to check an object, then when you press the “E” key the camera displays a picture of the object up close, here’s an example (sorry for the low quality, I found these images online):

I already have something that kinda works, like the title suggests I’m using a camera with a plane with a picture in front of it, so this brings me to the original question.

How to make this plane fill the screen completely?

Is this the right way to achieve this effect?

and just to clear things up a little, I have to use pictures instead of the full 3D objects because the models are really high quality so having many in a scene is not wise that’s why I cant just have the camera zoom in to the 3D object, even if using lods sometimes you see the lods rendering when zooming in. I hope i made it clear why I need to use images instead of the zoomed 3D mesh .

Thanks in advance.