A common problem encountered in using projected visual aids is:

Keystoning is a common issue observed when using projected visual aids, particularly when the projector is not aligned correctly with the surface onto which the image is projected. This misalignment results in an image that appears distorted, often taking the shape of a trapezoid rather than a rectangle. This distortion occurs because the projector is angled upward or downward instead of being parallel to the projection surface, leading to a loss of clarity and comprehensibility of the visual content.

Addressing keystoning typically involves adjusting the projector's placement to ensure it is level with the projection surface or utilizing keystone correction features if available. By managing keystoning effectively, educators can improve the overall effectiveness of their presentations, ensuring that students receive clear and accurate visual information that enhances their learning experience.