CCTV CCTV Camera Technology and Optics

Question 1

What does the term 'focal length' refer to in CCTV camera lenses?

Accepted Answer

The distance from the lens to the image sensor where parallel rays converge

Answer

Focal length is the distance from the optical center of the lens to the image sensor when focused at infinity, determining the field of view.

Question 2

Which camera type is best suited for a wide-area indoor space requiring a 360-degree view?

Accepted Answer

Fisheye camera

Answer

Fisheye cameras use an ultra-wide-angle lens to capture a full 360-degree hemispherical view, ideal for large indoor areas.

Question 3

What is the primary advantage of a varifocal lens over a fixed lens in CCTV?

Accepted Answer

Adjustable focal length without disassembly

Answer

Varifocal lenses allow the installer to manually adjust the focal length within a specified range, providing flexible field-of-view setup.

Question 4

What does 'WDR' stand for in CCTV camera specifications?

Accepted Answer

Wide Dynamic Range

Answer

WDR (Wide Dynamic Range) allows a camera to capture detail in scenes with both very bright and very dark areas simultaneously.

Question 5

Which sensor type is commonly used in modern IP cameras for converting light into electrical signals?

Accepted Answer

CMOS

Answer

CMOS (Complementary Metal-Oxide-Semiconductor) sensors are widely used in modern IP cameras due to their low power consumption and high integration.

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