The perspective group allows the user to change the perspective of the molecule as well as turning on the full screen mode.
The Orthoscopic On and Off buttons allow the user to turn orthoscopic perspective on and off. With orthoscopic on, PyMol gives the correct proportions to the view, and with orthoscopic off, these proportions are abandoned in lieu of a greater sense of depth.
The Set Field of View slider allows the user to manually select the field depth. Clicking the Update button will incur the change to the field of view, based on the setting of the slider.
Fullscreen Mode makes the PyMol view window full screen and also hides the internal GUI associated with the viewer. There is no way to turn the full screen mode off in PyMol or EZ-Viz, so getting out of full screen can be a trick. It is suggested to use Alt + Tab to access the Pymol Tcl/Tk GUI shown on the start bar, and to close all of Pymol just close this window.