Ask Proxima C300HB User Manual

Page 2

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

projector?

The image offset for this projector is 90%.

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 the entire 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.

4:3 aspect ratio—In 4:3 aspect ratio, the offset value is 90%. This means that the top of the image is above the lens plane

when the projector is mounted on the ceiling (or below the lens plane when placed on a tabletop, as shown above).

16:9 aspect ratio—At a 16:9 aspect ratio, the bottom of the image is higher than when projected in 4:3 ratio—.125 of the

4:3 image height. This is because a 16:9 image that is the same width as a 4:3 image is also one-eighth smaller on the top
and one-eighth smaller on the bottom.

Calculating image offset— The 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 image offset for 4:3 aspect ratio, multiply the image height x .90. For a 50" tall

image, the top of the image will be the distance between the ceiling and the lens plane less 4.5".

NOTE You can find the image height by using the ASK Proxima Projection Calculator.

What kind of screen should I use with this projector? Can I use a light colored wall?

First, for best results, we do not recommend casting images (especially video) on a light colored wall. While you will certainly

get a viewable image, the color reproduction will not be accurate. Wall textures may also create image artifacts.

What screen you use depends on the viewing audience and the amount of light in the room (ambient light). Say the seating

arrangement requires that you have a wide viewing angle and that the room has some ambient light. Choose a screen with a

lower gain (for example, a DaLite HC-Da-Mat, a gray screen with 0.8 gain). If your viewing angle is narrower, you can

choose a higher gain screen (for example the Stewart Grayhawk). Higher gain screens are also better for images larger than

100" wide. One issue to be aware of is that the higher the gain on a screen, the more likely you will notice "hot-spotting" and

sparkles in the image. You should work with your screen supplier to make sure you get the appropriate screen for your
circumstances. Find more information at DaLite Screen Company or Stewart Filmscreen Corporation.