I have the option to start with child of shadow (move ten feet and you are considered concealed as shadows wreath you) and nimbus light.

nimbus light is 15 feet of light (5 normal and 10 shadowy).

Assuming direct line of sight, if its night and im in the woods, and have the numbus active, could something from 50 feet away see me?

(still night time) If I am moving and using Child of shadow, giving me concealment, how close would they need to be before they get to try to see me?