turning brightness down makes the game scarier
by activating the console commands and turnign the brightness down from there allows you to bring the back to the brightness it had way back when in 2004. now that i have lowered the brightness i found that it helps compencate for the fact that the lights it attached to your armor. it is very scary now and though i played through it a lot back on the original xbox version i find this game scarier because it has a lot of areas the original xbox verson was missing.
to initiate the console for the game go to the games launche options in properties and type this in: +seta com_allowconsole 1. this will allow you to use the console in doom 3 bfg edition (disclaimer: you wont be able to collect acheivments after this code has been used in launch options)
here is the command you use to lower the brightness: +set r_lightscale 1
if this doesnt work let me know. it has been a while since i typed this code in so i will have to do some work to find it again