[mr.miyagi]

try fov_desired 90 if you get motion sickness or just fancy a change of field of view, I changed to 90 and I prefer it now. The default is 75 and the max is 90

you enter it into the console, which is enabled in controls > advanced

Example:

FOV 75
http://www.notworksafe.com/ctf_2fort0003.png

FOV 90
http://www.notworksafe.com/ctf_2fort0004.png

I think it writes it to the cfg file so you should only need to do it once and is of course easily reversed rock: