Question 1

The pupil of the eye increases in size under which condition?
A)eye is focused on a distant object
B)eye is focused on a nearby object
C)object viewed is dimly illuminated
D)object viewed is well illuminated

Accepted Answer

The pupil of the eye increases in size in dimly illuminated conditions to allow more light to enter the eye and improve visual acuity.

Question 2

Tripling the focal length in a telephoto lens,while keeping the aperture size constant,will change the f-number by what factor?
A)1/9
B)1/3
C)3
D)9

Accepted Answer

The f-number is calculated as the focal length divided by the aperture diameter. Tripling the focal length while keeping the aperture size constant will triple the f-number.

Question 3

A 1.6-m tall woman stands 7.0-m in front of a camera with a 6.0-cm focal length lens.What is the size of the image formed on film?
A)26.3 cm
B)1.9 cm
C)1.4 cm
D)67.2 cm

Accepted Answer

C

Question 4

The ciliary muscle is instrumental in changing the shape of which eye part?
A)iris
B)lens
C)pupil
D)retina

Accepted Answer

The ciliary muscle helps to change the shape of the lens in the eye, specifically by relaxing or contracting to adjust the tension on the suspensory ligaments that hold the lens in place. This process, known as accommodation, allows the lens to focus light onto the retina and adjust for near or far vision. The iris regulates the amount of light entering the eye by changing the size of the pupil, but it does not affect the shape of the lens. The retina is the layer of cells that detects light and sends signals to the brain, but it is not involved in changing the shape of the lens.

Question 5

A diverging lens will be prescribed by the eye doctor to correct which of the following?
A)myopia
B)presbyopia
C)hyperopia
D)astigmatism

Accepted Answer

A diverging lens (also known as a concave lens) is used to correct myopia, which is a condition where the eye is too long or the cornea is too curved, causing distant objects to appear blurry. A diverging lens helps to spread out the light entering the eye, allowing the image to be focused properly on the retina. Presbyopia is a condition associated with aging where the eye loses its ability to focus on near objects, hyperopia (or farsightedness) is a condition where distant objects appear clear, but near objects are blurry, and astigmatism is a condition where the cornea is not perfectly round, causing distorted vision. None of these conditions would be corrected by a diverging lens.

Question 6

Tripling the f-number of a camera lens will change the light intensity admitted to the film by what factor?
A)1/9
B)1/3
C)3
D)9

Accepted Answer

The light intensity is proportional to the square of the f-number, so tripling the f-number will cause the intensity to decrease by a factor of (3)^2 = 9. Therefore, the correct choice is A) 1/9.

Question 7

Tripling the focal length of a telephoto lens,while holding aperture size constant,will change the light intensity admitted to the film by what factor?
A)0.11
B)0.33
C)3.0
D)9.0

Accepted Answer

The answer of Tripling the focal length of a telephoto...

Question 8

A camera has a lens of focal length 70 mm and a speed of f/2.0.What is the diameter of the lens?
A)17.5 mm
B)35 mm
C)70 mm
D)140 mm

Accepted Answer

The diameter of the lens can be calculated using the formula: 
Diameter = Focal Length / f-number 
where f-number is the ratio of the focal length to the aperture diameter. 
Given that the focal length is 70 mm and the speed is f/2.0, the f-number can be calculated as: 
f-number = focal length / aperture diameter = 70 / (aperture diameter/2) = 140/aperture diameter 
Therefore, aperture diameter = 140 / f-number = 140 / 2.0 = 70 mm 
So, the diameter of the lens is 70 mm. Choice C is therefore incorrect. 
To obtain the correct answer, we have to recall that the f-number is the ratio of the focal length to the aperture diameter. A lower f-number means a larger aperture diameter, which in turn means more light can enter the lens. Since the lens in this question has an f-number of f/2.0, it has a relatively large aperture diameter. This means that the correct answer should be smaller than the focal length of 70 mm. The only choice that satisfies this condition is B, 35 mm.

Question 9

A camera lens is initially set at f/32 for a shutter speed of 1/15 s.If the amount of lighting on the subject is unchanged,and the lens is set at f/16,what is the proper shutter speed at this setting?
A)1/60 s
B)1/2 s
C)1/125 s
D)1/30 s

Accepted Answer

When the lens setting is changed from f/32 to f/16, the light entering the camera is doubled (since f/16 is twice as wide as f/32). To maintain the proper exposure, the shutter speed must be halved (doubled shutter speed means half the amount of time the sensor is exposed to light). Therefore, the proper shutter speed at f/16 setting would be 1/60 s, which is half the shutter speed of 1/15 s at f/32 setting. The other choices are incorrect as they do not take into account the relationship between aperture and shutter speed in maintaining the same exposure.

Question 10

I take two pictures of my dog Kaycee.I use the same film and level of illumination for both pictures,but I triple the f-number for the second picture.By what factor will the required time of exposure change if the film is to receive the same total light energy?
A)0.11
B)0.33
C)3.0
D)9.0

Accepted Answer

The exposure time is proportional to the square of the f-number. Tripling the f-number increases the exposure time by a factor of 3^2 = 9.

Question 11

A low f-number:
A)allows a smaller depth of field.
B)allows using a faster shutter speed.
C)causes less spherical aberration.
D)is not related to any of the above options.

Accepted Answer

A low f-number (e.g. f/1.4, f/2) allows a larger opening of the lens, which in turn allows a smaller depth of field. This means that only a small portion of the image will be in focus, while the rest of the image will be blurred. This effect can be used creatively, but it can also make it difficult to achieve sharp focus throughout the entire image.

Question 12

Changing the f-number of a camera by three stops by going from f/5.6 to f/16 will change the intensity of the light hitting the film by a factor of:
A)8.
B)4.
C)1/4.
D)1/8.

Accepted Answer

The intensity of light hitting the film is inversely proportional to the square of the f-number.

So, going from f/5.6 to f/16, the change in f-number is (16/5.6)^2 = 8, which means the intensity of light hitting the film decreases by a factor of 8.

Therefore, the answer is D) 1/8.

Question 13

A camera is used to photograph the full moon,which has an angular diameter of 0.51 $\degree$.The image on the film is 3.2 mm in diameter.What is the focal length of the lens?
A)3.2 mm
B)720 mm
C)360 mm
D)1130 mm

Accepted Answer

The angular diameter of the moon is 0.51 degrees. Using the formula for angular size, θ = (d / f) * (180/π), where d is the image diameter and f is the focal length, we can solve for f: f = (d * 180) / (θ * π). Substituting d = 3.2 mm and θ = 0.51 degrees, we find f ≈ 360 mm.

Question 14

The ciliary muscle of the eye is relaxed under which condition?
A)eye is focused on a distant object
B)eye is focused on a nearby object
C)subject being viewed is well illuminated
D)subject being viewed is dimly illuminated

Accepted Answer

The ciliary muscle is relaxed when the eye is focused on a distant object. This causes the suspensory ligaments to pull tight, flattening the lens and allowing for clear vision of faraway objects.

Question 15

Doubling the aperture diameter of a camera lens will change the light intensity admitted to the film by what factor?
A)0.25
B)0.5
C)2.0
D)4.0

Accepted Answer

Doubling the aperture diameter increases the area of the aperture by a factor of four (since area is proportional to the square of the diameter), thus increasing the light intensity by a factor of four.

Question 16

Quadrupling the aperture diameter of a camera lens will change the f-number by what factor?
A)1/16
B)1/4
C)4
D)16

Accepted Answer

The f-number is inversely proportional to the aperture diameter. This means that as the diameter of the aperture increases, the f-number decreases.

When the aperture diameter is quadrupled, it means that it is multiplied by 4.

Therefore, the f-number will be divided by 4 (since it is inversely proportional).

So, the answer is B, which represents a change in the f-number by a factor of 1/4.

Question 17

Which term below identifies the eye defect characterized by an inability to see distant objects clearly?
A)myopia
B)presbyopia
C)hyperopia
D)astigmatism

Accepted Answer

Myopia, also known as nearsightedness, is the eye condition where distant objects appear blurry while close objects can be seen clearly. This is due to the light focusing in front of the retina instead of directly on it.

Question 18

What is the f-number of a camera lens that has an aperture-opening diameter of 0.10 cm and a focal length of 1.0 cm?
A)0.10
B)0.1
C)10
D)1.0

Accepted Answer

The answer of What is the f-number of a camera...

Question 19

A converging lens will be prescribed by the eye doctor to correct which of the following?
A)farsightedness
B)glaucoma
C)nearsightedness
D)astigmatism

Accepted Answer

The answer of A converging lens will be prescribed by...

Question 20

A camera uses a:
A)converging lens to form a real image.
B)converging lens to form an imaginary image.
C)diverging lens to form a real image.
D)diverging lens to form an imaginary image.

Accepted Answer

A camera uses a converging lens to form a real image on the film or sensor. This converging lens gathers and focuses light from the scene being photographed, creating a sharp and clear image on the film or sensor.

Quiz 25: Optical Instruments

The pupil of the eye increases in size under which condition?

Tripling the focal length in a telephoto lens,while keeping the aperture size constant,will change the f-number by what factor?

A 1.6-m tall woman stands 7.0-m in front of a camera with a 6.0-cm focal length lens.What is the size of the image formed on film?

The ciliary muscle is instrumental in changing the shape of which eye part?

A diverging lens will be prescribed by the eye doctor to correct which of the following?

Tripling the f-number of a camera lens will change the light intensity admitted to the film by what factor?

Tripling the focal length of a telephoto lens,while holding aperture size constant,will change the light intensity admitted to the film by what factor?

A camera has a lens of focal length 70 mm and a speed of f/2.0.What is the diameter of the lens?

A camera lens is initially set at f/32 for a shutter speed of 1/15 s.If the amount of lighting on the subject is unchanged,and the lens is set at f/16,what is the proper shutter speed at this setting?

I take two pictures of my dog Kaycee.I use the same film and level of illumination for both pictures,but I triple the f-number for the second picture.By what factor will the required time of exposure change if the film is to receive the same total light energy?

A low f-number:

Changing the f-number of a camera by three stops by going from f/5.6 to f/16 will change the intensity of the light hitting the film by a factor of:

A camera is used to photograph the full moon,which has an angular diameter of 0.51 $\degree$ .The image on the film is 3.2 mm in diameter.What is the focal length of the lens?

The ciliary muscle of the eye is relaxed under which condition?

Doubling the aperture diameter of a camera lens will change the light intensity admitted to the film by what factor?

Quadrupling the aperture diameter of a camera lens will change the f-number by what factor?

Which term below identifies the eye defect characterized by an inability to see distant objects clearly?

What is the f-number of a camera lens that has an aperture-opening diameter of 0.10 cm and a focal length of 1.0 cm?

A converging lens will be prescribed by the eye doctor to correct which of the following?

A camera uses a: