Too little light in photos

[hobbyrv]

I am trying to make photos of my design. When I choose the better quality, there is too much shadow and very little light. I've tried all the settings mentioned in the guide, without result, it stays too dark. When I see other examples of photos, they are better. I can't figure out what I'm doing wrong. Who helps me out?
And I also want to know whether it is possible to let(indirect) lightning shine in the photo. I see it only in the ceiling light, which I can't replace. I also want to make it possible with lamps.

[HawkDawg]

You can add light fixtures to your plan, then add light bulbs to those fixtures from the Lights category.
The bulbs can then be adjusted to your needs from the various types of bulbs to their intensity [Light power (%)], location and size.