Benq MP780 ST User Manual

Page of 99
Positioning your projector
18
How to determine the position of the projector for a given 
screen size
1.
Select your screen size.
2.
Refer to the table on page 
and find the closest match to your screen size in the 
left columns labelled 
. Using this value, look across this row to the right to 
find the corresponding average distance from screen value in the column labelled 
. This is the projection distance.
3.
On that same row, look across to the right column and make note of the 
 value. This will determine the final vertical offset placement of the 
projector in relation to the edge of the screen.
4.
The recommended position for the projector is aligned perpendicular to the 
horizontal center of the screen, at the distance from the screen determined in step 2 
above, and offset by the value determined in step 3 above.
For example, if you are using the MX750 and a 120-inch screen, the average projection 
distance is 4420 mm and with a vertical offset of 274 mm. If you are using the MP780 ST and 
a 120-inch screen, the average projection distance is 1274 mm and with a vertical offset of 
202 mm.
How to determine the recommended screen size for a 
given distance
This method can be used for situations where you have purchased this projector and would 
like to know what screen size will fit in your room.
The maximum screen size is limited by the physical space available in your room. 
1.
Measure the distance between the projector and where you want to position the 
screen. This is the projection distance.
2.
Refer to the table on page 
and find the closest match to your measurement in the 
average distance from screen column labelled 
. Check that your measured 
distance is between the min and max distances listed on either side of the average 
distance value.
3.
Using this value, look across that row to the left to find the corresponding 
 
listed in that row. That is the projected image size of the projector at that projection 
distance.
4.
On that same row, look across to the right column and make note of the 
 value. This will determine the final placement of the screen in relation to 
the horizontal plane of the projector. 
For example, if you are using the MX750 and your measured projection distance is 3.0 m 
(3000 mm), the closest match in the 
 column is 2947 mm. Looking across this row 
shows that a 80-inch screen is required. If you are using the MP780 ST and your measured 
projection distance is 3.0 m (3000 mm), the closest match in the 
 column is 2698 
mm. Looking across this row shows that a 250-inch screen is required.
If you place the projector in a different position (to that recommended), you will have to tilt 
it down or up to center the image on the screen. In these situations, some image distortion 
will occur. Use the Keystone function to correct the distortion. See 
 on page for details.