Epson 100" EpiqVision Ultra LS500 4000-Lumen Pixel-Shift 4K UHD 3LCD Laser Projector TV System with 100" Screen (White Projector) - Manual (Page 66)

66
affected by small movements. Adjust the projector's position in small increments to square up the image.
If this isn't possible, use the keystone correction buttons on the projector to correct the image shape.
Note: Wait 20 minutes after turning on the projector before setting the focus for maximum accuracy.
1. Turn on the projector and display an image.
Note: You can display a pattern to aid in adjusting the projected image using the Settings menu.
2. Press one of these keystone buttons on the control panel to display the Keystone adjustment
screen.
3. Press a keystone button on the projector's control panel to adjust the image shape.
Vertical
Horizontal