What is the term used for the distortion of an image that results when a projector and screen are not aligned correctly?

Keystoning refers to the distortion that occurs when a projector is not aligned with the screen correctly, leading to a trapezoidal image instead of a rectangular one. This typically happens when the projector is placed at an angle to the screen, causing the top of the projected image to appear wider or narrower than the bottom, or vice versa. Proper alignment is crucial for a clear and accurate representation of the projected content.

In contrast, blurring generally relates to the focus of the image and could occur even with proper alignment if the lens adjustments are not made correctly. Focusing specifically involves adjusting the projector to enhance image clarity, while fringing usually describes color distortions or halo effects around an image's edges rather than alignment issues. Understanding these distinctions highlights the importance of keystoning in achieving a high-quality projection.