Image Calibration: Focus, Keystone & Corner Correction
How to get a clean, square, sharp image on real-world surfaces: motorized focus, keystone and 4-corner geometric correction explained step by step.
Order Matters
Always calibrate in this order: 1) physical aim → 2) keystone/corner → 3) focus. Correcting geometry after focusing will require re-focusing.
Physical Aim
Position the unit as perpendicular to the surface as the bracket allows. The more you rely on electronic correction, the more resolution you sacrifice — aim well first.
Keystone
If the unit is mounted off-axis (e.g., angled down from a wall), the image becomes a trapezoid. Use keystone (up to ±15°) to square it. Keystone is symmetric — it suits centered tilts.
4-Corner / Grid Correction
For asymmetric setups — corners of rooms, pillars, irregular walls — use 4-corner correction: drag each corner of the test pattern onto the physical corner of your target area. For curved or complex surfaces, grid (mesh) correction warps the image in finer detail.
Focus
Finish with motorized focus from the remote: sharpen at the center, then verify edges. With short-throw and angled setups, depth of field is asymmetric — prioritize the zone where people look and interact.