Epson PowerLite Pro Cinema 4040 User Manual page 79

You see this screen:
14. Select Adjust the four corners and press Enter.
15. Use the arrow buttons on the remote control to adjust the color alignment in the corner of the screen
highlighted by the orange box.
16. Press the Enter button to move to the next corner of the screen.
17. When you are finished adjusting each corner of the screen, press Enter.
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