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Which of the following has an incorrect characteristic of the types of CCTV irises that are available?

CCTV lenses have irises, which control the amount of light that enters the lens. Which of the following has an incorrect characteristic of the types of CCTV irises that are available?

i. Automated iris lenses have a ring around the CCTV lens that can be manually turned and controlled.
ii. A lens with a manual iris would be used in areas that have fixed lighting, since the iris cannot self-adjust to changes of light.
iii. An auto iris lens should be used in environments where the light changes, as in an outdoor setting.
iv. As the environment brightens, this is sensed by the manual iris, which automatically adjusts itself.

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A.
ii, iii

B.
i, iv

C.
i, iii

D.
ii, iv

Explanation:
CCTV lenses have irises, which control the amount of light that enters
the lens. Manual iris lenses have a ring around the CCTV lens that can be manually
turned and controlled. A lens with a manual iris would be used in areas that have
fixed lighting, since the iris cannot self-adjust to changes of light. An auto iris
lens should be used in environments where the light changes, as in an outdoor
setting. As the environment brightens, this is sensed by the iris, which
automatically adjusts itself. Security personnel will configure the CCTV to have a
specific fixed exposure value, which the iris is responsible for maintaining. On a
sunny day, the iris lens closes to reduce the amount of light entering the camera,
while at night, the iris opens to capture more light-just like our eyes.


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