No, that site is not accurate.
On the site it lists VS1 as being the measurement from the TOP of the projected image. Then it gives lens shift from the CENTER of the projected image.
VS1 actually is calculated this way:
VS1 = .63 x (image height) - (.5 x (image height))
More accurately:
VS1 = .13 x (image height)
As I stated in my prior post which meand without using keystone correction, you can place the projector's center lens about 5" above the top of the screen on center.
Lens shift is an optical process. The lens assembly is physically moved up and down to adjust the location of where the image will appear on the wall. Lens shift usually is centered on a projector so that at a neutral '0' position the projector will sit exactly halfway up/down a screen and will be projecting an image that is equidistant above, below, and side to side of the center of the lens. A multiplier then lets you know how far up you can move it. For the AE700 that multiplier is .63 times screen height. You do not tilt the projector at all, you simply move it straight up and keep the projector perfectly level. As long as you don't move it up (or down) more than .63 times screen height, you do not have to use keystone correction.
KEYSTONE CORRECTION - This is when you actually physically tilt the projector down or up (or side to side). As soon as you tilt the projector you will see that one end of the image is wider than the other end. In your case, if you tilt the projector down, you will see that the bottom of the image is wider than the top of the image. To correct this, digital circuitry processes the image so that a non-square image is projected. That is, instead of 1280 pixels being used top to bottom, the top of the projected image is 1280 pixels wide, and the bottom of the image may only be 1180 pixels wide. Then, from top to bottom more and more pixels are removed from the image.
Obviously, this immediately causes image degradation because pixels that are available, are not being used.
On the other hand, the AE700 still looks really good with some digital keystoning in use. It most definitely affects image quality though and was something I tested for the first time I put my hands on the projector. I turned keystone correction on to the lowest value and could (barely) see a slight drop in image quality where the correction was taking place. (bottom of the screen)
It is something I recommend that people try to avoid and one of the reason the AE700 and Z3 were so popular. The InFocus SP4805 and Optoma H31 are great machines, but without lens shift and a good zoom range, they are much more critical to place correctly.
The Z3 most of all offerred a LOT of lens shift which make it much more ideal for a situation like you are in. Many also considered the Z3 to have a superior image to the AE700 - which is of course, debatable.
If you have already received the AE900 then you can easily check the full extent of the lens shift out just by plugging in an extension cord and pulling out a ladder and projecting on your wall.
CAD is nice, but it is far easier, quicker, and (IMO) more accurate to see results by simply hooking it up and seeing what height looks best to you.
If you have NOT ordered the AE900 - then perhaps waiting for the Z4 is in order?
