What are adjustable focus systems called?

What are adjustable focus systems called?

• A. Fixed focus
• B. Mechanical focus
• C. Digital focus
• D. Phased array

Answer: (D)

Adjusting focus electronically is the hallmark of a phased array. In a phased array, many small emitters or elements work together, and by delaying or advancing the signal (changing the phase) for each element, the waves combine constructively at a chosen point to form a focused beam. You can also steer that beam by tweaking the relative phases, all without moving parts. That real-time, electronic control of focus and direction is what defines an adjustable focus system. Fixed focus relies on a single, unchanging focal length. Mechanical focus changes the focus by physically moving a lens. Digital focus simulates or enhances focus through processing after the image is formed. None of these adjust the focus by phase control across an array the way a phased array does.

Adjusting focus electronically is the hallmark of a phased array. In a phased array, many small emitters or elements work together, and by delaying or advancing the signal (changing the phase) for each element, the waves combine constructively at a chosen point to form a focused beam. You can also steer that beam by tweaking the relative phases, all without moving parts. That real-time, electronic control of focus and direction is what defines an adjustable focus system.

Fixed focus relies on a single, unchanging focal length. Mechanical focus changes the focus by physically moving a lens. Digital focus simulates or enhances focus through processing after the image is formed. None of these adjust the focus by phase control across an array the way a phased array does.