| Keystone correction horizontal |
If a projector cannot be placed in the right angle to the screen but due to space-saving reasons at a side, the distortions in an image are adjusted with an image processor. |
| Keystone correction vertical |
Many digital projectors project as a presetting in a certain angle upwards to minimize the keystone effect. Some devices have an additional keystone correction, that means an image processor calculates the distortion-free image of the front - or downwards projection. Only a few devices resolve this optically (Lens Shift function). |
| Keystone effect |
Trapezoid image distortions with front or downwards projections. Can be corrected with tilted projection screen and/or with keystone correction. |
