Put this in Documents\My Games\Fallout 76\Fallout76Custom.ini

[Controls]
bMouseAcceleration=0
fIronSightsPitchSpeedRatio=1
fPitchSpeedRatio=1
[Display]
iSize H=1080
iSize W=1920
fDOFBlendRatio=0
fDOFMinFocalCoefDist=999999
fDOFMaxFocalCoefDist=99999999
fDOFDynamicFarRange=99999999
fDOFCenterWeightInt=0
fDOFFarDistance=99999999
fIBLensFlaresBloomint=0
uIBLensFlaresBloomradius=0
[ImageSpace]
bDoRadialBlur=0
iRadialBlurLevel=0
bDoDepthOfField=0
bDynamicDepthOfField=0
bMBEnable=0
[General]
sStartingConsoleCommand=saveini