looks like postprocess shader of dayz got a mistake in it, since each time adaptation changes from "darker" to "brighter" we can see tonemapping lagg (color out of range - "black sun")

its easy to fix - just put one line right after tonemapping:
outcolor.rgb = saturate(outcolor.rgb); , this will clamp the possible output from 0...1 that corresponds LDR

also this may happen due to odd adaptation ranges and sensibility