CurtPalme.com Home Theater Forum

[rtart]

Hi,

Sort of a dumb question, but one that I have thought about a while. How do you ensure that the PJ is square to the screen? I mean REALLY accurately placed?

Using a tape measure and a side wall as reference, getting very close on putting the PJ in the center of the room pretty straightforward. However, squaring up the PJ seems to be more of a challenge. I've basically measured to the center of the PJ's green lens from a side wall, then marked the middle of the screen using the same distance from the same side wall. Then I put the vertical green center pattern on the center mark I made on the screen wall.

After this, if the screen wall and the side wall are square, and the green raster is centered on the tube, the PJ's image should be square to the screen wall as well?

I've considered using a laser level to physically check alignment of the PJ's case and/or mounting brackets with the screen as well, but it seems to me that the method described above should work as well.

Is there a simple way to check that the PJ is square to the wall after doing the method above? If the room is not square (could happen) it will obviously throw off any adjustments and could cause problems going forward.

Again, kind of a dumb question, but if it ain't square to start with, it ain't never gonna be set up correctly.

[Elaine Benes]

Crossed corner measurements all need to be exactly the same.

I measure from the top corner of the screen to the opposite front and rear corner of the projector, then do the same from the other top corner of the screen. That gets the projector both centered and squared to the screen. Who cares how its oriented to the walls, its how its oriented to the screen that matters...

[jeffslife]

I am REALLY no expert , but first of all what kind of pj do you have?
Is your screen mounted to the wall? Is the wall your screen?
IS your pj floor mounted or ceiling mounted?

[rtart]

[jeffslife]

Elaine-benes is absolutly correct.
if your pj is floor mounted height is important too,
also a ROCK SOLID base that NEVER moves.

[jeffslife]

sounds like its all good to me, enjoy!

[rtart]

[garyfritz]

IMHO this is by far the easiest and most accurate way to square the projector:

Sight along a square edge of the projector, or maybe along the feet -- anything that's known to be perpendicular to the pj-to-screen line. A laser pointer can be helpful for this, but I think sighting is best. Measure where that sightline hits on both walls. (I taped "measuring sticks" on the wall -- I drew a "ruler" on a piece of paper, and taped it on the wall so the 120" mark on the ruler was exactly 120" from the screen. Then I could just look to see where on the ruler the sightline fell.) Adjust the PJ until the sightline-to-screen distance is the same on both sides.

It's very easy to get the PJ aligned within 1/8 degree that way.

[rtart]

Great idea! This compensates for non-square walls.

[akajester]

I like your method Gary. Very simple and effective.

Dale

[Artinaz]

This method works mostly with the NECs which has the cross test pattern. Hold a mirror against the screen. If its indeed square, the green vertical line will reflect back to the center of the green tube.

[AnalogRocks]

I use to do that with my 1252. I moved it allot so I had 2 pieces of string, one off each front corner. I'd set up the tripod screen and stretch out the two pieces of string to the screen and I was square. I usually didn't even need to adjust focus. It felt like cheating

[AnalogRocks]

I use to do that with my 1252. I moved it allot so I had 2 pieces of string, one off each front corner. I'd set up the tripod screen and stretch out the two pieces of string to the screen and I was square. I usually didn't even need to adjust focus. It felt like cheating

[ecrabb]

I prefer a tape measure and a laser level to get evrything down to the gnat's ass.

Here are a couple more threads on the topic.

https://www.curtpalme.com/forum_archived/viewtopic.php@t=12056.html

https://www.curtpalme.com/forum_archived/viewtopic.php@t=12911.html

SC

[CasetheCorvetteman]

Its only cheating if you get caught Jeremy