Light has no halo?

Hello, here is a render of a cube with a powerful red emission material, and there is a point lamp on the left.

Why can’t I see the halo like in the preview ?
image

Do I need another object to reflect the light ? Can’t I see the halo in the void ? thank you in advance for your answers.

Yes, the “halo” you see in the material preview in the object illuminating the floor underneath it.

Yes! Then how can I make it visible in the void ? I’ve seen others do this. For example :


Thank you in advance.

Hello. I think adding Volume scatter fixed the issue. But now, I have a new problem, so I’m going to make another thread, so that the title is still relevant to the problem. Anyway, thank you for your answer !