Which of the following require more critical beam centering?

Question

Quizplus · Accepted Answer

Focused grids require more critical beam centering because the grid strips are angled and aligned to the path of the divergent beam. If the beam is off-center, it will miss the grid strips, resulting in increased scatter radiation and decreased image quality. Parallel grids do not require as much precision in beam centering because they are perpendicular to the path of the beam. Low-ratio and low-frequency grids may require some degree of centering, but not as much as focused grids.

Which of the Following Require More Critical Beam Centering