Physical Setup

The other night I swapped my old and not particularly good and stable Duronic mount for a peerless PRG-UNV which meant i had MUCH better control of physical adjustments and as such managed to get a nigh on perfect alignment of the projector to the screen.

My screen is slightly odd being suspended on wires and getting parallel holes across the width of a room perfect is neigh on impossible, meaning the screen is slightly off axis.

To be honest getting perfect projector and screen alignment with measurements, even with lasers and spirit levels and so forth is massively tricky.

The below method eschews normal methods and uses easy visual cues and large differences to make it a doddle to get a much more accurate alignment

Axis used

Since describing adjustments can be tricky, this is fairly universal aid to what i'm describing. Just think of the PJ like a plane with the screen in front of the nose

Set Keystone to zero. Bring up the internal alignment pattern.

Using zoom make the picture reasonably small on the screen and use the lens shift back and forth to get it the image in the middle of the settings (The epson doesn't have a value, hence this step). This gives the biggest scope in all directions for adjustments

ROLL

Hang an extended tape measure from the top of the screen, roughly in the middle, the weight on the end keeps it true and it makes a nice quick DIY plum bob. Move the central line close to the tape using lens shift, this will give you an idea of how level the pj is.

Adjust so the top and bottom of the line are an equal distance from the tape as per image (the thicker black line is my tape hanging down)

PITCH- Tilt

Move the pattern so one vertical edge is close to the screen edge.

Adjust the tilt of the projector until the top and bottom of the edge line is perfectly parallel to the screen edge.

Eg for the left, so points A and B are equal to the edge at the top and bottom of the image.

YAW - twist

With the pattern close to the lower and top of the screen, twist the projector until the horizontal edge is parallel.

Eg for the top, so points A &B are equal to the edge

(and yeah i cheated for the image)

If you follow the above you will have a level image and all four corners perfectly placed

The adjustments mean switching back and forth between lens zoom and lens shift a fair bit and doing visual comparisons. It may need a little of switch back and forth between Pitch and Yaw as you bring the image into perfect alignment without the need of the Keystone setting (0) which causes image degradation unlike lens shift which you are free to use.

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