Computer screens give off lighting, but not nearly enough to light your scene correctly. You'll need to bring in some lights to not only get a proper exposure but to also make sure you're in control of the look at all times.
In this tutorial, the team over at The Film Look walk you through their process of lighting a night scene with moody computer screen lighting without having a ton of space to work with. Check it out below:
Even though shooting in cramped spaces can be a bummer, it's not impossible. There are a bunch of clever techniques and tools you can use to squeeze enough light into your tiny little set.
The Film Look team used a few different lights: a key light, hair light, and a background light. Don't freak out about having to get your hands on a bunch of studio lighting equipment though. You can totally get away with some budget LED lighting.
And the cool thing about this lighting tutorial is that it shows you how to utilize the light from your computer screen as not only a stylish practical but also as a sidelight that produces a nice, dramatic look.
Don't forget, you're gonna need to block any light that you don't want interfering with your shot. Primarily, that means blacking out windows with some heavy, dark, dense material, like blackout curtains.
Once your space is nice and dark, you'll be able to paint with light like the cinematic Caravaggio you are.
Source: The Film Look