AVS Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
78 Posts
Discussion Starter · #1 ·
Little confusion with lens shift. I'm not sure how to calculate the max horizontal lens shift I'm going to get with a VS Pro8100. If I have a 96" screen with a 11/12 foot throw how many inches from the center (0 lens shift) can I mount the projector?


Basically I'd like to mount my projector as close to the wall as possible. The wall is 65 inches from the center of the screen now.


Thanks!
 

·
Registered
Joined
·
13,326 Posts
65" below or above the center of the screen? Maybe I am confused.


I don't see how this is possible. Generally you can't be much if any above or below the top / bottom edge of the screen.
 

·
Registered
Joined
·
60 Posts
JBS:


The Viewsonic has 10% horizontal lens shift, 5% in either direction. Thus, for a 96" wide screen, the lens can be offset from the center by 9.6".


If you mount by the wall and need 65" of horizontal shift, you will need to use keystone correction.


Hope that helps!!
 

·
Registered
Joined
·
13,326 Posts
Good to know. I just assumed the lens shift was a wide ranging as the Panasonic Projectors.

I set them up all the time at the top of most screens, right side up.
 

·
Registered
Joined
·
874 Posts
The vertical shift on the Pro8100 is quite large. For a 120" screen, you can mount the projector up to about 18" above the top of the screen. However, it's the horizontal shift that is limited. Use of both vertical also has an impact on horizontal. The good news is that the lens is huge, so you're almost always in the sweet spot. I'm not aware of any projector that can handle a 65" horizontal offset, unless you do like hooters suggested and aim it sideways a bit and use keystone correction.
 

·
Registered
Joined
·
60 Posts
JBS:


The only projector that may have a large enough horizontal shift is the Epson 8100. I recall reading Art's review that it was the most flexible in terms of positioning. Not sure what it is capable of but if it can't do it then it likely cannot be done.


Good Luck!!
 

·
Registered
Joined
·
78 Posts
Discussion Starter · #7 ·
Thanks everyone for the information. It was very helpful. Luckily I am demoing a Epson 8100 and Pro8100.


Another question:


If I do use lens shift to the max am I hurting image quality at all? I know if I use digital lens shift or keystoning that I'm hurting quality.


Thanks!
 

·
Registered
Joined
·
874 Posts
You will likely see degradation sooner on the Epson, because it has a smaller lens (smaller sweet spot) and lower quality optics (plastic versus glass). However, it also has a larger range of horizontal shift, so it may in fact be at or near the same location as the Pro8100. The only way you'll know for sure is by testing both. I can tell you that my Pro8100 remains razor sharp to just prior to the very limit of available shift. Even then, although not as sharp, it's still quite usable and better than a lot of LCDs at their sharpest.
 

·
Registered
Joined
·
857 Posts

Quote:
Originally Posted by Dark Rider /forum/post/18284505


You will likely see degradation sooner on the Epson, because it has a smaller lens (smaller sweet spot) and lower quality optics (plastic versus glass). However, it also has a larger range of horizontal shift, so it may in fact be at or near the same location as the Pro8100. The only way you'll know for sure is by testing both. I can tell you that my Pro8100 remains razor sharp to just prior to the very limit of available shift. Even then, although not as sharp, it's still quite usable and better than a lot of LCDs at their sharpest.

Is this true for both the V. and H. shift--remaining razor sharp til almost at max shift? My install will require almost max V. shift with no H. shift.


Where are your calibrations settings posted? I can't locate the posting.


Thank you.


Henry
 

·
Registered
Joined
·
874 Posts

Quote:
Originally Posted by hmcewin /forum/post/18284918


Is this true for both the V. and H. shift--remaining razor sharp til almost at max shift? My install will require almost max V. shift with no H. shift.


Where are your calibrations settings posted? I can't locate the posting.


Thank you.


Henry

I'm using a bit of both, but definitely more horizontal than vertical. My PJ is shelf mounted in a separate projection/equipment room. The projector sits a little more than 2' up from the center point on my screen, and I have to shift left 8" on a 120" screen. I'm not sure that I've explored the limits of vertical, but I definitely have for horizontal when deciding where to cut my hole and build my shelf.


My calibration settings are here: http://www.avsforum.com/avs-vb/showt...9#post18240319 but I will warn you. We discovered that each and every Pro8100 receives a separate calibration in the service menu prior to leaving the factory. Chances are good that you will need to do some manipulating if you want it as accurate as possible. If accuracy isn't your top concern, you most likely will be able to make some tweaks based on your taste and be happy though.
 

·
Registered
Joined
·
282 Posts
I didn't want to make a new thread since this is regarding Vertical lens shift on this projector.


I have 80" ceilings (after the drop ceiling is installed).


If I go with the pro8100, it will be mounted 11' away, and I would like an image of 100" diagonal.


This would be ceiling mounted as close as possible to the ceiling, so probably about a 6" drop from the lens center, and I'm having trouble understanding what the 75% vertical lens shift means.


Would this setup work for me? My concern is that the image would not be able to be lowered enough to be not cut off by the ceiling...
 

·
Registered
Joined
·
874 Posts
You shouldn't have any problems with vertical lens shift, because there is no fixed offset to contend with. Without any vertical shift on the Pro8100, you would literally be mounted directly in the center of the screen. Since you are ceiling mounted, you will have a little bit of downward vertical lens shift, but not much at all due to your low ceilings. Your bigger constraint is going to be your throw distance. Is 11' from the front of the lens to the screen? If so, than you'll have no problems, but the Pro8100 will max out its zoom for a 100" screen at 10'3" and if you haven't heard, its a pretty large projector.
 

·
Registered
Joined
·
282 Posts

Quote:
Originally Posted by Dark Rider /forum/post/18285542


You shouldn't have any problems with vertical lens shift, because there is no fixed offset to contend with. Without any vertical shift on the Pro8100, you would literally be mounted directly in the center of the screen. Since you are ceiling mounted, you will have a little bit of downward vertical lens shift, but not much at all due to your low ceilings. Your bigger constraint is going to be your throw distance. Is 11' from the front of the lens to the screen? If so, than you'll have no problems, but the Pro8100 will max out its zoom for a 100" screen at 10'3" and if you haven't heard, its a pretty large projector.

The 11' is ballpark at the moment, but it will be AT LEAST 11' from the front of the lens, possibly 12'. I have a 22' room to work with, but am only dedicating a little over half of the room to the 'theater' area.


Thanks for the reply.
 

·
Registered
Joined
·
874 Posts
OK, then you should have no worries! The Pro8100 really is a killer projector for the price. I got mine nearly 6 months ago, and am still wowed every time I turn it on. It takes some tweaking to get it perfect, but it has more settings than any projector that I've ever seen, and it calibrates extremely well to D65/Rec709.
 

·
Registered
Joined
·
2,548 Posts
So what is the ideal distance for a 100" screen with this project? Is it as far backas it cna go or as close? I feel like the closer the better for light output, but I think the zooming somehow conunteracts this? (Even though I think zoom would be needed further away, not closer?)


Thanks,

John
 

·
Registered
Joined
·
3,276 Posts
From what I've read, less zoom is better. With that being said, the Pro8100 is very bright, even in Eco mode. Mine is at ~12" on a 110" screen and even during the daytime w/ some lite coming in, I still use Eco mode w/ no problem.
 
1 - 16 of 16 Posts
Top