Which statement about depth of field and magnification is true?

• A. It increases with magnification
• B. It has no relation to magnification
• C. It decreases with magnification
• D. It increases and decreases unpredictably

Answer: (C)

The concept here is how depth of field changes with zoom. Depth of field is the range of distances that appear acceptably sharp in the image. As you increase magnification, that sharp zone becomes narrower. Higher magnification magnifies not only fine details but also any slight misfocus or variations in the stone’s depth, so the tolerable focus window shrinks. In practical terms, you’ll see less of the diamond in sharp focus at higher magnification and may need to refocus more often as you sweep across surfaces. That’s why the statement is true: depth of field decreases with magnification. The other ideas—no relation, increasing depth of field, or an unpredictable relationship—don’t align with how optical focus works.