WorksheetsCHAPTER 5 – LENSES
Total questions: 20
Worksheet time: 10mins
What are the main functions of a lens on a camera in a surveillance system?
Brighten dark images
Provide better lighting
Defining the field of view
Define the image sensor format
How does the amount of light passing through a lens affect the quality of the picture in a surveillance system?
The amount of light does not affect the quality of the picture
The less light that passes through, the better the quality of the picture
The more light that passes through, the worse the quality of the picture
The more light that passes through, the better the quality of the picture
Why is the selection of a lens critical in a surveillance system?
It only affects the lighting of the image
It has no effect on the size, shape, and sharpness of the image
It directly affects the size, shape, and sharpness of the image
It indirectly affects the size, shape, and sharpness of the image
How does a varifocal lens differ from a fixed lens?
A varifocal lens offers a range of focal length, while a fixed lens only offers one focal length
A varifocal lens allows the user to manually adjust the camera's lens, while a fixed lens cannot be adjusted by the user
A varifocal lens is recommended for outdoor conditions, while a fixed lens is recommended for indoor conditions
A varifocal lens is not recommended for outdoor conditions, while a fixed lens is recommended for outdoor conditions
In which type of environment is a fixed lens typically used?
Indoor environments where the iris needs to be adjusted
Outdoor environments where the viewing angle needs to be adjusted
Outdoor environments where the scene lighting is constantly changing
Indoor environments where the viewing angle does not need to be adjusted
Why are zoom lenses recommended for outdoor conditions?
They offer the best housing for the lens
They offer a range of focal length that needs manual adjustment
They automatically adjust the amount of light reaching the camera
They are normally deployed in areas where viewing angle adjustment is not required
What is the iris and what is its function in a camera?
A device that controls the aperture of the lens
A device that controls the sensitivity of the sensor
A device that controls the shutter time of the camera
A mechanical device that adjusts the amount of light passing through the lens of a camera
How does the aperture size in the iris affect the amount of light that passes through the lens?
The aperture size affects the depth of field of the image
The aperture size does not affect the amount of light passing through the lens
A smaller aperture size allows more light to pass through, while a larger aperture size allows less light to pass through
A larger aperture size allows more light to pass through, while a smaller aperture size allows less light to pass through
How does the iris size affect the depth of field in an image?
A small iris diameter gives a better depth of field
A large iris diameter gives a better depth of field
The iris size affects the shutter time of the camera
The iris size does not affect the depth of field of the image
How is the iris size measured in a camera?
In pixels
In inches
In F-number
In millimeters
What is an auto-iris and when is it typically used?
A type of iris that is not adjusted and is used when light sources are not steady
A type of iris that is adjusted with a ring on the lens and is used when light sources are steady
A type of iris that is adjusted with a button on the lens and is used when light sources are not steady
A type of iris that can automatically adjust the amount of light entering and is mainly required for outdoor applications or places where lights change frequently
In which type of environment or conditions is the auto-iris typically used?
Indoor applications or places where lights change frequently
Outdoor applications or places where lights change frequently
Indoor applications or places where lights do not change frequently
Outdoor applications or places where lights do not change frequently
What is the main difference between CS-mount and C-mount lenses?
The thread size
The flange focal distance
The number of glass components used
The distance from the lenses to the sensor
What is the relationship between the f-number and the lens' light-gathering ability?
The f-number increases the lens' light-gathering ability
The f-number has no effect on the lens' light-gathering ability
The larger the f-number, the better the lens' light-gathering ability
The smaller the f-number, the better the lens' light-gathering ability
How does the f-stop relate to the depth of field and the amount of light needed for an image?
A small f-stop corresponds to a small depth of field and less light needed
A large f-stop corresponds to a large depth of field and less light needed
A large f-stop corresponds to a small depth of field and more light needed
A small f-stop corresponds to a large depth of field and more light needed
What is depth of field and what does it refer to?
The focal length of the lens
The amount of light needed to capture an image
The distance between the camera and the subject, where objects appear sharp
The distance in front of and beyond the point of focus where objects appear sharp
How is the field of view determined in a camera?
By the f-number of the lens
By the focal length of the lens
By the size of the image sensor
By both the size of the image sensor and the focal length of the lens
What is the advantage of a narrower field of view in an image?
It provides less distortion
It provides more details
It provides a wider angle view
It provides better low-light performance
What type of lens is typically used for a surveillance object that is small or located far away?
Fisheye lens
Telephoto lens
Wide angle lens
Normal view lens
What factors determine the angle from which a lens accepts light to focus on the image sensor?
The focal length and aperture of the lens
The focal length and size of the image sensor
The size of the image sensor and the aperture of the lens
The size of the image sensor and the f-number of the lens
