I found another spot where this bug is happening. This time it was on the Insurgent side, approaching F from the east side; at the location I am standing, the screen went much darker, and stayed that way for a little while:

Specs:

CPU: i7 4790k
GPU: GTX970 4GB
RAM: 32GB DDR3 @ 1866mhz
HDD: Samsung 840 SSD

lmao I played through refinery a few times thinking "oh wow did they add dynamic time of day to maps?"

I literally thought the map got darker as evening was coming!

This is happening for me on other maps too, though not as extreme as on Refinery, and also increases brightness sometimes. When you Escape to Menu and go back the brightness normalizes again. It's a bug that i've reported in a less extreme version for the pre Nov 7th version already.

Solution by other players(credit to original founder) :
When you looking at dark thing(like floor/rock/smoke) press escape and resume.

Thanks for this, have passed it along

it happens on all maps in my experience, i think it is caused by UE4's Eye adaption (Auto exposure). i think i show just be turned off as its just not accurate and fast enough to be a net positive, i just find it distracting.