The scopes I use…
http://www.majhost.com/cgi-bin/gallery.cgi?f=278994
http://www.majhost.com/gallery/Tango/AoS/Scopes/Basic/semi.png
http://www.majhost.com/gallery/Tango/AoS/Scopes/Polarized/semi.png
http://www.majhost.com/gallery/Tango/AoS/Scopes/NightVision/semi.png
REGULAR - Use wherever
POLARIZED - Use in maps that might be a bit foggy or dark colored. It will help you see better.
NV - Use in maps with day/night scripts. Otherwise, its useless.