1) adjust your range of side to side screen position from one extreme to the other, then make sure you are in the center of this range of movement. Then physically rotate the projector to center the image on the screen. It sounds like you may have your projector aimed to the right and are compensating with the lens side/side adjustment. This will allow for (+) vertical keystone on the right side of the screen, which you have noted.
You must always have the projector vertically and horizontally square to the screen to eliminate keystone and allow the lens shift to work properly.
When a projector has keystone when perfectly square to the screen, the solution is to move or rotate or elevate the projector in the direction of the (+) keystone and then use the lens shift to center the image back on the screen. You will begin to see the keystone reduce.
It's a little confusing, but you might get a better handle on the relationship if you experiment with various projector angles and screen position settings on a larger white wall, then you will be able to see keystone changes and how they relate projector alignment and screen position controls.
Good luck
You must always have the projector vertically and horizontally square to the screen to eliminate keystone and allow the lens shift to work properly.
When a projector has keystone when perfectly square to the screen, the solution is to move or rotate or elevate the projector in the direction of the (+) keystone and then use the lens shift to center the image back on the screen. You will begin to see the keystone reduce.
It's a little confusing, but you might get a better handle on the relationship if you experiment with various projector angles and screen position settings on a larger white wall, then you will be able to see keystone changes and how they relate projector alignment and screen position controls.
Good luck





















(and your obvious experience) I am interested in these "squishy" subjective impressions.

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