Runco SC-30d Benutzerhandbuch

Projector and/or screen placement — among other things — can cause geometric 
distortion in the projected image. 

To correct this, the Dimension Digital Controller provides precise, nine-point control over 
the projected image geometry. Use these controls as (and only if) needed to re-position 
the image corners, mid-points and center to eliminate “keystoning” (mis-aligned corners) 
or “pincushion” distortion (mid-points not aligned with corners). See Figure 3-27.