What is the image offset of the 4805 and the HD1000U? Thx!

The HD1000 is 35% of screen height. The 4805 is less but im not sure by how much

I believe the 4805 offset is 27.5%.

From an FAQ on the Sp4805:

Q: How far from the table top or the ceiling is the image cast by this projector? What is the image offset for this projector?

A: What is image offset? The 'image offset' percentage for a projector tells you where the image will appear in relation to the plane of the lens. An image offset of 0 means that half of the image is above the lens plane and half is below. An image offset of 100% means that all of the image is above the lens plane, with the bottom right at the lens plane. An offset value of more than 100% means that the image appears a distance above the lens plane, or below the lens plane if the projector is mounted on the ceiling (pictured below).The image offset for the ScreenPlay 4805 is 127.8%.Why have image offset?GInFocus adds image offset so the image can be projected at a good viewing level, and still maintain its rectangular shape. In other words, with image offset, you avoid keystoning, where the image is larger on top than on the bottom.Calculating image offset GThe image offset amount varies, depending on how far away the projector is from the wall and by how big the image is. To calculate the amount of offset, multiply the image height times .278. (Note: you can find the image height by using the InFocus Projection Calculator). For a 50" tall image, the top of the image will be the distance between the ceiling and the lens plane plus 13.9".Note: you can find the image height by using the InFocus Projection Calculator.