DONT CLICK DOWNLOAD, GET THE FILE HERE - skyrim-beautification-project.com/stalker/clear_sky/ ......Realistic field of view for Clear Sky Playable. Quick 'n' easy install. See description.
Original download of this version of xrGame.dll - Steamcommunity.com
Installation - Copy+Replace xrGame.dll to your bin folder in the game directory (backup the original beforehand). Avoid any loading issues by taking ownership/unblocking/unticking read only and archived in properties.
Vanilla field of view (garbage):
90 field of view: