What angle is the target set at?

What angle is the target set at?

• A. 5-8 degrees
• B. 20-25 degrees
• C. 30-35 degrees
• D. 12-15 degrees

Answer: (D)

Setting the target at about 12–15 degrees gives a practical balance between a clear line of sight and stable, accurate alignment. This moderate tilt helps align the instrument with the target’s plane, improving depth perception and reducing parallax error. If the angle is too shallow (5–8 degrees), depth cues are limited and small misalignments become more likely. If it’s too steep (20–25 or 30–35 degrees), the target can sit out of the instrument’s optimal focal range, increasing the chance of off‑axis errors or shadowing. So, around 12–15 degrees is typically chosen to optimize accuracy and repeatability.

Setting the target at about 12–15 degrees gives a practical balance between a clear line of sight and stable, accurate alignment. This moderate tilt helps align the instrument with the target’s plane, improving depth perception and reducing parallax error. If the angle is too shallow (5–8 degrees), depth cues are limited and small misalignments become more likely. If it’s too steep (20–25 or 30–35 degrees), the target can sit out of the instrument’s optimal focal range, increasing the chance of off‑axis errors or shadowing. So, around 12–15 degrees is typically chosen to optimize accuracy and repeatability.