These patchers change FOV (field of view) to 90 by direct editing of the xrgame.dll. Copy it to the BIN folder of the game and run one of patchers corresponding to your game version. Game
This tutorial shows mod beginners how to make a little mod. It included a dds-plugin for Adobe Photoshop and for GIMP 2.0. You can download this if you don\'t now much about moding in S.T.A.L.K.E.R.