1. adjusted or set to focus in advance; having the focus already established before use
Usage: chiefly British spelling (American: prefocused); technical term used in photography, optics, and imaging

Examples

• The prefocussed camera lens allowed the photographer to capture the moment without delay.
• Modern smartphones often use prefocussed sensors to ensure sharp images.
• The microscope came with a prefocussed objective for immediate observation.
• Prefocussed binoculars are convenient for quick wildlife viewing.
• The telescope's prefocussed eyepiece made setup faster for amateur astronomers.