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Discussion Starter · #1 ·
Hi all,


I'm just about to mount my BD808 with unistrut.

I have a couple of questions though.


The screen width is 214cm (about 84") and the screen height is 115cm, going for an AR of 1.85:1 (bad idea, doesn't matter ?)


If I calculate with the LENS program, the PJ should be about 302cm from the screen and the A value is -22.7cm.


I hate that A value ;)

If we look at a ceiling front mount and the A value is -22.7cm how long should the rods be ?

I want the screen to be about 40cm below the ceiling.

At the same time I want the rods to be as short as possible since the PJ will take "visual space" in the room if it's mounted low.


In the lens program it also states an angle of 10.5, is that the angle it will have or is it something that I need to angle myself ?
 

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The angle is set at 10.5 if you level the projector. Note that you can slighly adjust the front and rear from level if you need to make some slight adjustments but I would not go far from level. The A value is tough to understand, especially since it sometimes shows in the wrong direction on the chart. I dont have the program on this computer so I will refer to it when i get home. In the meantime maybe others can chime in. I recently asked similar questions and there are a number of posts about the lens program if you do a complete search specifying all possible responses.


Brian
 

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I just installed a BD808s in my home this Sunday. I had the same issues as you are facing. If I lower the projector enough to allow it to set level it will be too low. I tilted the projector enough to allow the image to be centered on my screen while still keeping the image in the center of the raster.


When I am in calibration and I have a genlocked pattern displayed I have an out of focus condition on the bottom of the image. I don't know of anyway to solve this. What I did do was turn the outer focusing ring on the lens to produce the best focus possible between the top corners and the bottom of the image. If I then do a good job of convergence setting the resulting picture while the projector is in use is very good.
 

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Discussion Starter · #4 ·
If I understand this correct, I need to lower the PJ 22.7cm to have the picture from the ceiling and down. If I want the screen to be 40cm from the ceiling then I need to lower it 62.7cm ?

Or does the program still calculate it on a 4:3 AR even though I manually entered the SW and SH ?
 

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Discussion Starter · #5 ·
bump....


Need help with the stupid/fine program LENS ;)

Do I need to lower the PJ 22.7cm from the ceiling ?

If I want the screen to be 40cm from the ceiling do I need to lower the PJ 62.7 cm ?
 

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Actually, I think you need to lower the projector by 17.3 cm. From memory, my A value is roughly 7.6 inches and I have the projector hanging on five inche rods to project on the wall 12.6 inches below the ceiling. Brian
 

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I believe usabrian is correct. The -22.7cm would be required to position the top of the image at your ceiling height. Since you want the image at +40cm below the ceiling height you would subtract the A value from the desired height of the top of the image. This is how far you need to lower the projector. This will work as long as you only wish to view 16/9. I don't think 4/3 will work in this configuration.
 

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I too had this problem. I fixed it by tilting the front of the PJ down about 2" (ceiling mount) and pulling the bottom of screen away from the wall about 6". works great.

Scott
 

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Discussion Starter · #9 ·
Yeah, I think you're right.

You (I that is ;) ) have to think of it as the other way around.

Stupid program, or they should have an option for screen height placement. Couldn't be that hard to incorporate into the program.
 

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Discussion Starter · #10 ·
When everyone is talking about the risk/chance that the PJ might fall from the ceiling, everyone is discussing the Unistrut and what type of joist it's mounted to.

I looked under the PJ and the only thing that keep the feet/mount points under the PJ from coming loose is 4 small screws on each foot.

How safe is this thing ;)
 
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