CPSC 425 Image Formation, Cameras and Lenses 20 (Term 2) Practice Questions
Multiple Part True/False Questions. For each question, indicate which of the statements, (A)–(D), are true and which are false? Note: Questions may have zero, one or multiple statements that are true.
Question 1: Which of the following statements are true of a pinhole camera? Which are false?
(A) A pinhole camera is a box with a small hole in it.
(B) Images in a pinhole camera are upside down.
(C) A pinhole camera has a fixed focal length, f .
(D) Images in a pinhole camera are a perspective projection.
Solution : (A) True, (B) True, (C) False, (D) True.
Question 2: Which of the following statements are true of an actual pinhole camera. Which are
(A) It takes too long to acquire an image.
(B) It uses an orthographic projection.
(C) It works only for black and white (B&W), not for colour.
(D) It has too small a depth of field (i.e., too small a range of object distances for which the image is in sharp focus).
Solution : (A) True, (B) False, (C) False, (D) False.
Question 3: Lens vignetting is a type of image distortion. Which of the statements, (A)–(D), are
true of lens vignetting and which are false?
(A) Vignetting is a slight curvature of straight lines away from the center of the image.
(B) Vignettingisashiftincolourowingtothevaryingrefractionoflightatdifferentwavelengths. (C) Vignetting is a darkening of an image towards its edges.
(D) Vignetting makes it difficult to bring all parts of an image into focus at the same time.
Solution : (A) False, (B) False, (C) True, (D) False.
Question 4: Consider Snell’s law. Which of the following statements are true? Which are false?
(A) It describes how light bends when passing from one material into another. 1
(B) It describes how fast light travels in one material compared to another.
(C) It describes the angle at which light bounces off a mirror surface.
(D) It describes how much light is reflected and how much passes through the boundary between two materials.
Solution : (A) True, (B) False (but it allows one to calculate the speed from observing the bend- ing, so “sort of” True) (C) False, (D) False.