Screenshot question

I know how to take a screen shot on the PC (print screen button), where to find the files (searched for "screenshots") and how to go to first person mode to control whether my character is in the shot or not. What I can't figure out is how to remove all of the UI elements to take those great landscape shots.

Help?

Edit: Thanks for the help! Scroll lock it is!

Hide UI element with "Scroll Lock". Middle button next to PRINT SCRN.

it should be defaulted to 'scroll lock.' try that..