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Hi,

This is my first post here. Great forum! I just bought a BENQ W5000 as my first projector. However, I'm noticing a difference between what I observe, and what is in the manual. This has to do with lens shift. What I seem to have is the opposite of what the manual shows. I seem to have -120, +80 lens shift. The manual diagrams show the opposite. I have my projector rear mounted on a shelf at almost roof height sitting on it's feet (FEET DOWN). Anyhow, I can get the top of the image projected to be 20% below the projector level, when I put the lens shift as far downward as I can get. When I put it upward as far as I can get, the bottom of the projected image about 20% below the level of the projector lens. In other words, it would be IMPOSSIBLE to ceiling mount the projector without a drop tube or keystone. Can anyone else check and confirm if their projector is the same? I've found the following reference that indicates that it may well be normal, and the manual may be incorrect in terms of it's diagram.

It's from the projector central review:

"The vertical lens shift of two picture heights is perfectly adequate for almost all rear shelf mounted installations. If you ceiling mount, you may find that a drop tube is required in order to avoid tilting it and using keystone to square up the image."


Here is a diagram from the Benq Manual:


Here is a diagram that I drew of what I'm getting:


It works fine for me in it's current configuration. However, I worry that If I move and am forced to ceiling mount it, it'll become a bit of a pain.


So, is there something not right with my BENQ's lens shift, or is it a mistake on the manuals part? The way I see it, they've cocked up the diagram anyway haven't they? The 120% regardless of whether it's positive or negative shift should be the top of the image, not the center line. The same could be said for the 80%. Correct?


Thanks,

Bevan
 

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Discussion Starter · #2 ·
No answers? Surely someone can quickly check this for me on their W5000. I'm getting rather worried about it, and wondering if I should take it in. Or, is my lens shift range normal?!



Bevan
 

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I was wondering the same thing with my W when I first got it.

I never tested how far it goes upward but downward it definitely goes over 100%. My projector lens is now at about the same level as the top of the screen and there would still be room to lower it, so I estimate mine goes to about -120% too.


I definitely prefer the way how this actually works. I could have live with just 80% downward shift but the screen would definitely be a tiny bit too high for my neck. What a nice suprise, well done BenQ!
 

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I just got my w5000 today and after reading your thread/question i decided to try it, however because i only just got it, i only quickly mounted it on my coffee table just to see the image and if all works etc...

Now after trying the lens shift, its a bit confusing, how do you tell where 0% lens shift is? or any other number?

Mine seems to go down more than up, but without seeing any numbers on the screen and/or measuring the image on the screen and marking it etc , its hard to tell!


I wanted to zero my lens shift but now i dont know how...
 

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My W5000 is ceiling mounted, and the top of the projected image is below the center line of the lens. The percentages quoted in the manual are 1/2 height of the image, so will full shift I get around 4.5 inches of shift below the center line with a screen height of 45.5" (45.5 * 1/2 * .2 = 4.45). I have never tried the shift in the other direction as it has always been ceiling mounted.
 

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4500 posts is a bit difficult to sift through for a specific problem.


I'd just like to add that I researched it and read that the W5000 had +120/-80 lens shift, but then when I queried this with Benq tech help I was told that it was in fact +100/-100...then when I checked out the demonstrator model where I bought my W5000 it was definitely +120/-80 (a full foot below center)...so I bought mine, built my mount accordingly, hooked it all up...AND MINE WAS +100/-100 LIKE THEY SAID ON THE TECH LINE!!!!!


I have the funny feeling that they were still playing around with this part of the design during production.


So I'm left with keystone turned on, and a whole re-mount ahead of me.
 
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