Press the "3D Screenshot" hotkey whilst playing the game. By default the hotkey is set to the "PrtScn/SysRq" key. Alternatively, open the TriDef 3D Ignition OSD (see Q9) and select "3D Screenshot from the menu.
3D Screenshots are stored in the users default "Pictures" directory. After successfully taking a 3D Screenshot, a message will appear near the bottom left hand corner of the display showing the location of the screenshot. Each 3D Screenshots is stored in several formats including anaglyph, SideBySide and TriDefPhoto.