Horsekoch

I think so. I have not got to venture into the depths yet. But one time I have cranked it up to 0.50 and everywhere was bright, either under the sky or inside my house.

In 'clientsettings.json' you can decrease the darkness level. Navigate to 'floatSettings' section, and change 'minbrightness'. I set mine to 0.04 to simulate slight illumination from the moon.