A FOV meter of around 85-90 is best for 1st person games, played on standard PC monitor (19-21") with keyboard and mouse from around 50-70 cm distance.
Many developers (like Bethesda) tend to make the annoying mistake to lock the FOV on 55-65 because of their console users who play with a gamepad from 1.50 - 3 meters away on their TVs. This however is very bad for serious PC gaming and can cause problems.
Mistaken FOV is the reason why there are some people with motion sickness who bash the 1st person idea and prefer to play in 3rd person. This is very bad for gaming industry, because the problem is tiny and it is easily fixed only if the game developer has the desire to help by simply adding FOV slider. Everyone could easily then adjust the picture to his liking and play FPS without any motion sickness.
More important, when FOV is right, 1st person perspective is a lot more enjoyable and immersive to play and don’t cause any troubles whatsoever.
Typing a console command or modding the game is possible indeed, but it is not a valid option for a strictly PC promised game like KC:Deliverance. IMO there should be a graphical slider which allows us to adjust the FOV between 50 and 100, so that everyone could set the FOV as he is most comfortable with based on his hardware and preferences.
And @Wenceslaus - warping the picture depends on many other factor rather than FOV alone - your screen type, resolution, game engine etc… Generally speaking, any FOV above 100 will warp the picture and cause the fish eye effect.
But as many other said above, FOV range about 85-90 is the best for a 1st person PC game - you gain volume and depth in your picture, have strong peripheral vision and don’t suffer from motion sickness without giving away anything from the gameplay and/or the immersion.
I sincerely hope @warhorse would add a slider for the next release.