Which setting widens the FOV past the in-game maximum?

In KFEngine.ini change AspectRatioAxisConstraint=AspectRatio_MaintainXFOV to AspectRatio_MaintainYFOV.

Why set the file to read-only?

The guide recommends it so the game does not overwrite your edit. To revert, change the value back or delete the file.

KF2: Increase Field of View Beyond the Slider Maximum

Killing Floor 2 lets you set the field of view with a slider in the options, but you can go wider with one config edit. This is a very short tweak: it takes a minute and can be undone at any time.

Steps

Adjust FOV normally with the in-game slider first.
Go to Documents\My Games\KillingFloor2\KFGame\Config and open KFEngine.ini in Notepad.
Find the line AspectRatioAxisConstraint=AspectRatio_MaintainXFOV.
Replace it with AspectRatioAxisConstraint=AspectRatio_MaintainYFOV.
Save the file and set it to read-only.

To revert, change the value back or delete the file so the game generates a fresh one.

KFEngine.ini with the changed AspectRatioAxisConstraint line The edited line in KFEngine.ini.

Second view of the edit and the read-only setting Marking the file as read-only.

Comparison

Both screenshots below use the maximum FOV from the in-game options, taken before and after the edit.

Before the config change Before.

After the config change After: a noticeably wider view.

Notes

The same line is also covered in the larger Tweaks and Improvements guide, which explains the difference between the Vert- and Hor+ field of view.

FAQ

Which setting widens the FOV past the in-game maximum?: In KFEngine.ini change AspectRatioAxisConstraint=AspectRatio_MaintainXFOV to AspectRatio_MaintainYFOV.
Why set the file to read-only?: The guide recommends it so the game does not overwrite your edit. To revert, change the value back or delete the file.