Quiz For Lesson 3:

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Question 1: An optical error that results in a failure of the light rays to all converge at the same point is called:

Dispersion
Aberration
Vignetting
Diffraction

Question 2: Which two principles of light account for the light losses in a lens system?

Absorption and refraction.
Absorption and reflection.
Absorption and dispersion.
Dispersion and refraction.

Question 3: The drawing below shows an incident ray of light striking a glass surface. What will be the angle of reflection?

This drawing is used for Questions 3 and 4.

Question 4: The incident ray in the drawing above:

Will not be refracted because of the angle of incidence.
Will not be refracted because of the critical angle.
Will be refracted towards the normal.
Will be refracted away from the normal.

Question 5: When an incident ray of light strikes a front-silvered mirror perpendicular to the mirror surface:

The ray does not reflect.
The ray reflects back upon itself.
The reflected ray travels along the surface of the glass.
The ray passes through the glass to form a virtual image.

Question 6: A positive lens forms an image of a point source of light:

At the focal point if the incident rays are parallel.
At the focal point if the incident rays diverge from the source.
At the focal point if the incident rays converge from the source.
In front of the focal point if the incident rays diverge from the source.

Question 7: If the point source of light is not at infinity, the positive lens causes the light rays to:

Converge at the focal point.
Converge behind the focal point.
Converge in front of the focal point.
It depends on whether the rays from the point source converge or diverge.

Question 8: The positive lens forms a real image:

When the object is outside the focal length.
When the object is inside the focal length.
When the object is either inside or outside the focal length.
Regardless of the object position.

Question 9: A plano-concave lens:

Can't form an image.
Forms either a real or a virtual image, depending on the object position.
Forms a real image.
Forms a virtual image.

Question 10: Stopping down the lens normally improves the image by reducing the effects of aberrations. Which of the following does NOT improve as you stop down the lens?

Spherical aberration
Astigmatism
Diffraction
Coma

Question 11: If you double the distance between the camera and the light source, the light reaching the camera decreases by:

¹⁄₂
¹⁄₄
¹⁄₈
¹⁄₁₆

Question 12: You're checking a camera that automatically sets the shutter speed. The lightbox is calibrated EV 15 at ASA 100. With the diaphragm opening set to f11, what shutter speed should the camera automatically program?

Question 13: A manufacturer of a lightbox states that the maximum light intensity is BV 11. At what ASA film speed is the maximum light level equivalent to EV 15?

Question 14: If you're using a 3X extender on a 50mm lens, what is the equivalent focal length?

Question 15: A flat mirror forms:

A virtual image.
A real image.
Both a real image and a virtual image.
Either a real image or a virtual image, depending on the object position.

Question 16: The corrector lens in a mirror-lens system:

Corrects for diffraction.
Corrects for image position.
Corrects for focal length.
Corrects for spherical aberration.

Question 17: The reflected ray in a prism travels along the surface of the glass when:

The angle of incidence causes total internal reflection.
The angle of incidence equals the critical angle.
The angle of incidence is greater than the critical angle.
The angle of incidence is less than the critical angle.

Question 18: You're testing the resolving power of an 80mm lens using the NBS Test Charts. How far should the lens be from the charts to obtain a 25X reduction?

Question 19: The following charts show two resolution-test results made at f4. In the spaces provided after the charts, name the aberration you would diagnose as causing the results.

1:

2:

Question 20: Answer the following statements true or false:

True
False