For FCC, if the horizontal lines are sharper at the beginning of the test, do you add plus lenses or minus lenses until both the horizontally and vertically oriented lines are equally sharp?

For FCC, if the horizontal lines are sharper at the beginning of the test, do you add plus lenses or minus lenses until both the horizontally and vertically oriented lines are equally sharp?

• A. Plus lenses
• B. Minus lenses
• C. No change
• D. Flip orientation

Answer: (A)

Balancing sharpness between the two perpendicular line orientations is the goal. When the horizontal lines look crisper at the start, you introduce plus power to the lens system. This shifts the focus in that meridian so its clarity decreases a bit, helping the horizontal and vertical lines come to the same level of sharpness. You continue adjusting until both orientations appear equally sharp. Using minus power would push the focus the other way and tend to widen the gap, while no change leaves the imbalance, and flipping orientation doesn’t address the focal balance.

Balancing sharpness between the two perpendicular line orientations is the goal. When the horizontal lines look crisper at the start, you introduce plus power to the lens system. This shifts the focus in that meridian so its clarity decreases a bit, helping the horizontal and vertical lines come to the same level of sharpness. You continue adjusting until both orientations appear equally sharp. Using minus power would push the focus the other way and tend to widen the gap, while no change leaves the imbalance, and flipping orientation doesn’t address the focal balance.