One of the mods that I've been using for a very long time is "Darker Interiors - Fear the Dark" by Rednaolrac. It removes (lowers) the ambient light value in almost all indoor / underground / interior cells to make the wasteland a much darker place when you're not outside. Which adds greatly to the atmosphere and makes the metro tunnels a really scary place to be without a light (or night vision goggles).

However, I'm finding that it's just too dark most of the time. Even with the "Nightvision Goggles - Powered" mod at 2x brightness, there's just not enough ambient light in the underground / indoor cells to make it possible to see what is going on.



So I went looking at the mod using both "Fallout 3 Edit" and the "Garden of Eden Creation Kit™ (GECK)". For the most part, Rednaolrac is setting most of the cell ambient light values to 1:1:1 (RGB), which is basically complete darkness. Realistic maybe, but it doesn't play out well given the limitations of in-game possibilities of implementing night vision goggles using "ImageSpace Modifiers". While the NVGs do amplify the brightness of the cell, a setting of 1:1:1 just doesn't provide enough brightness to work with.

In comparison, I looked at "Xepha's Darker Nights", which does something similar for the outdoor areas. The lowest values that Xepha sets for ambient light in the outdoor areas is in the range of 7-10 for each RGB value. Which works extremely well with NVGs, because there's enough light to work with.



So, I dug out the GECK editor and did a bit of editing to the Darker Interiors mod. First, I established a baseline of what an interior area looks like using the ambient light of 1:1:1 with the NVGs at the default brightness. I also tried out the "Pipboy Light Mod" with the color set to "Grey" and the range set to "3X". That mod is also extremely useful because it makes the light thrown off by the Pipboy (when you press and hold the [Tab] key) have a greater range of a few meters instead of only 1-2 meters.



Next, I tried the brighter version of the NVGs. Even with the 2x brightness increase from the NVG mod, there's still not enough ambient light for it to function well with Darker Interiors.



Leaving the NVGs set to double-brightness, I moved on to another indoor location with the default ambient light of 1:1:1, but this time I changed the cell's ambient light value to 2:2:2 using GECK. It's still very dark, and the change simply isn't enough to show.



So I went back and upped the ambient values to 5:5:5. This worked extremely well and suddenly the NVGs became a lot more useful. The shadows are still dark enough that you need some sort of light source to really see what you're doing, but there's enough residual light there to give the NVG's Image Space Modifier something to work with.



Note: In-game brightness will still be a bit better then what is visible in the YouTube videos. With something in the 4:4:4 or 5:5:5 range, you can read the GNR graffiti on the wall with the NVGs. And even without the NVGs, you can see just enough to realize that there is something there.

Now that I've played with a few more hours, I have some good recommendations:

- Anything lower then 4:4:4 is too dark for the RGB ambient light setting in a cell.

- Values of 4:4:4 to 6:6:6 are ideal for cells where it should be nearly pitch black in the shadows. So places like caves, metro tunnels, basements are all good locations to use something in that range. An auxiliary light source like NVGs or the Pipboy light are still necessary. The "4" is very dark, the "6" is only somewhat very dark. Both will appear pretty much pitch-black to the player if they have their system configured correctly.

- Values of 8:8:8 up to around 12:12:12 make the use of NVGs or a light source mod somewhat optional, but still extremely beneficial. I tend to use that range for indoor cells where there might be sunlight streaming in from a crack / hole. Or for locations which were recently occupied. Things like Germantown Police HQ, Willy's Grocer or the Museum of Technology. Places where lower level players are likely to go should be towards the upper-end of this range. At 10-12, you can see things and maybe make out details, but at 8, it's going to just be a dark shape if it's lying in a shadowed area.

- For occupied locations, you probably don't want to go darker then 12:12:12 up to 24:24:24. One example of this is the GNR (Galaxy News Radio) Lobby, which is occupied by the Brotherhood of Steel. Yet the Darker Interiors mod used a very dark ambient light value here. I bumped the value for this location up to 10:10:15, but I'll probably take it even farther up to 24:24:24. The default from the Fallout3.exm is 45:45:45 for the GNR Lobby. When you get up to around 20:20:20 or brighter, an alternate light source isn't needed - except when you want to examine something closely. I'm using values in the 15-25 range for inhabited areas, and the value of 24 that I used for the GNR lobby is on the bright end of moody.

- A lot of times, I just take the default Fallout3.esm value and divide by 10 and round down. Maybe bumping the numbers up/down a bit to keep the same approximate colors. Sometimes I'll divide by 5 or 8 or 12 depending on what the original values were.

I haven't decided yet what to do with the modified ESP files that I now have. I need to go through and rework the Pitt and Point Lookout, to make them more consistent with the changes I've already made. Waiting to see what reply I get to the comments that I made on Fallout3Nexus.