[vkottas]

so I'm waiting on my screen to arrive and have already mounted my Sony HS-20 on a ceiling mount (actually mounted to a shelf mounted to the wall).


the mount (from perfectmounts.com) allows for adjustment in all three axes. two of the axes are easy - just use a level to get the projector parallel to the ground (e.g. level) and hope that the opposing wall is perfectly vertical.


how can I accurately get the rotation of the projector right (e.g. rotating it about the vertical axis - making it "look left" or "look right") so that it is staring at the middle of the opposing wall? I can look for keystoning but it seems like a very delicate, arbitrary approach.


once I have the projector facing perfect to the wall I can trace the spot on the wall and mount the screen.


any hints?


-vas

 

[jojowasher]

what I did is measure from the back corners of the projector to the wall, and made sure that both corners were the same distance away.


Jojo

 

[vkottas]

thanks jojowasher.


that sounds like a great trick. one small challenge - the Sony HS-20 has a completely rounded back end, but I can probably do the same trick with the front corners.


just have to be extra careful (maybe use a level to keep the ruler straight, etc.)


any other ideas? that was a great one.

 

[Creekside]

Try it the other way. Measure the distance from the projector mounted wall to the center of the lens to the wall edge, and assuming the room is equal size, then mount the screen with the middle of it at the same point on the screen wall as the projector lens. Then level the screen. Turn on the projector and align it to the screen on all axis. Worked for me.

 

[vkottas]

another great suggestion.


I just have to watch room abnormalities. I once measured up from the floor to place to rear surround speakers and when I got done mounting they looked crooked because the ceiling (top of wall) was crooked.


based on that, any room measurements will start from the floor.


has anyone used something like a perfect corner (e.g. t-square) to check the geometry of the projected image? that seems like the ultimate sanity check, taking into account all wierd room angles.


-vas

 

[ZedZ]

I use a five beam self leveling laser level -- Helps a huge deal

 

[pbfoote]

Creekside's method will get you very close. If you want true perfection try the following. While in zoom mode, watch the center crosshair as you zoom in and out. If your alignment is perfect the crosshair will move up and down, without any left to right movement. Any left or right movement indicates an error. Adust your yaw or roll until you get it travelling straight up and down.

 

[vkottas]

ZedZ - I looked up 5-beam leveling lasers.


WOW - cool piece of equipment. As a tiny apartment dweller who doesn't do much handiwork, I can't justify the expense for this one little project. the one-beam versions seem to be had for as little as $20-30 - I might pick one of those up.

pbfoote - thanks for yet another excellent trick.


-vas