Tips on how to choose a home theater projector--Keystone Correction.

by Chelsea . on April 07, 2022

What is Keystone Correction

In the daily use of the projector, the position of the projector should be at right angles to the projection screen as much as possible to ensure the projection effect. If the verticality of the two cannot be guaranteed, the picture will be trapezoidal. Then you need to correct the picture at this time to ensure that the picture becomes a standard rectangle, which is keystone correction. 

The principle of keystone correction

There are generally two methods of keystone correction: optical keystone correction and digital keystone correction.

Optical keystone correction refers to adjusting the keystone by adjusting the physical position of the lens. Also called tilt-shift, the same as a tilt-shift lens for a camera.

Digital keystone correction is a geometric transformation of the original image by an interpolation algorithm to produce a reverse compensated trapezoidal image to compensate for the trapezoidal distortion of the image generated by the projection light path, making the projected image appear as a regular rectangle. 

Does Keystone Correction Affect Image Quality?

The picture quality after optical keystone correction basically has no change; while digital keystone correction will compress the picture. And after the image is corrected, some lines and character edges of the screen will appear burr and unsmooth phenomenon, resulting in the clarity of the screen being reduced.

When the requirements for image accuracy are not high, digital keystone correction can solve the problem of keystone distortion very well and is very practical, but it is not suitable for use when the requirements for image accuracy are high. So when we use the projector, try to ensure that the projector is right on the projection screen, so that you can enjoy the optimal picture quality.