Currently working on Monstrous Texture Mod, see my texture guide for more info
Guide For Textures

Fallout can have many shadow problems; ugly shadows, fast moving shadows of madness, shadow flickering.  I show you how to fix all, all while significantly reducing CPU and VRAM.  These presets also completely disable GodRays for further performance. This information is hours in the making and testing, so kindly give this mod the thumbs up.


If you are looking for a miracle flicker or shadow fix, this is it.
But try it before you post, it has, it will and it does work.
You will notice huge savings in CPU and significant FPS boost.


Fix all your shadowing problems by doing the following:
Nvidia / AMD users FXAA and  anti-aliasing must be completely turned off with your respective Nvidia/AMD control panel.
Make the following modifications to your Fallout4Prefs.ini:
sAntiAliasing=TAA
fLeafAnimDampenDistEnd=50.0000
fLeafAnimDampenDistStart=0.0000
iShadowMapResolution=3000
fDirShadowDistance=1500.0000
fShadowDistance=1500.0000
iVolumetricLightingQuality=-1
bVolumetricLightingEnable=0

These are the best settings that the game can use without visually glitching in some way.
If you want higher quality shadows increase iShadowMapResolution.
If you want shadows at greater distances increase fDirShadowDistance, and make fShadowDistance the same.
Save.

Make the following modifications to your Fallout4.ini:
bNvGodraysEnable=0
iShadowMapResolutionPrimary=3000
fSunUpdateThreshold:Display=20
fSunShadowUpdateTime=0.02
Save.

Make both files read-only.
All shadow problems should now be solved.

Please note: The file in the download section is a copy of the above.


Now to address some unintelligent criticism in the posts:
The game sets iShadowMapResolution to 3000 on medium shadows and 6000 on high shadows.
So take your base 2 argument and shove it where the sun don't shine; its
absolutely stupid unless you want to argue with the Devs.
And true Bethesda did do a piss poor job of implementing shadows, but anyhoo.
iShadowMapResolution=2048 produces shadow artifacts for me, others believe it does not or report
so but how closely are they inspecting?
I'll be even more specific, the problem I had with 2048 is that some shadows like those of bushes
and trees were on rampage despite the LeafAnim adjustment.  Finally, as I
stated unless you intend to use shadow values above 6000 the lack of
base 2 will have no effect on FPS.
So base 2 argument obliterated.  Before criticizing, THINK, THINK, and Think some more as you are about to take on a Tank.