sorry if i'm being dense! trying to make sense of things... if i understand correctly, objects which emit light (such as the turnip light) don't 'turn on' until you get close? i'm looking at your screen shot. i think it's 4 images side by side? are the 2 on left are before and after of each other? and so are the two on right? do the turnips go from the dimmer to brighter state as you get closer? and do they go from bright to dim again as you back up?

i've noticed sometimes when i first load into an area where i have a lot of lights and stuff there's bit of a delay as they're rendered in where they all look like they're unlit and then they all snap on.