Chapter 2 — Quiz

Twenty-five questions to check that the machine makes sense to you now: multiple choice, true/false (always with a justification — the reasoning is the point), short answer, and a few "what's wrong here?" diagnostic questions. Answer from memory first, then check the Answer Key at the end, where every answer carries a one-line explanation and a map of which section to review. Aim for understanding, not a score.

Multiple choice

1. Every camera, from a phone to a medium-format body, shares the same core parts. Which set names them correctly? - A) Lens, flash, viewfinder, memory card - B) Light-tight box, aperture, shutter, sensor (plus lens and processor) - C) Battery, screen, mode dial, tripod mount - D) Megapixels, ISO, focal length, white balance

2. In a pinhole camera, making the hole smaller causes the image to become: - A) Brighter and blurrier - B) Dimmer and sharper - C) Brighter and sharper - D) Dimmer and blurrier

3. A lens exists primarily to: - A) Make the camera look professional - B) Increase the megapixel count - C) Gather a lot of light through a wide opening and still focus it into a sharp image - D) Add digital zoom

4. A short focal length (e.g. 24mm) gives you: - A) A narrow angle of view and magnified distant subjects - B) A wide angle of view, fitting more in and making things look smaller/farther - C) More megapixels - D) A larger sensor

5. Which statement about zoom is correct? - A) Digital zoom and optical zoom produce identical quality - B) Optical zoom changes focal length and gathers real detail; digital zoom just crops and enlarges - C) Digital zoom is always better because it goes further - D) Prime lenses have the most powerful zoom

6. A photosite is best described as: - A) One dot of the final printed image - B) A single light-collecting well on the sensor that counts how much light fell on its spot - C) A colored filter - D) The lens's optical center

7. Two sensors have the same 24-megapixel count, but one is full-frame and one is phone-sized. The full-frame sensor will generally produce: - A) Lower resolution images - B) Identical images, since megapixels are equal - C) Cleaner images in low light, because its individual photosites are larger - D) More digital zoom

8. Because a bare photosite only counts light (it's "colorblind"), a camera produces color by using: - A) A larger lens - B) A higher ISO - C) A Bayer color-filter array over the photosites, then demosaicing to reconstruct the missing colors - D) The mode dial

9. In a standard Bayer array, which color has twice as many filters as the others, and why? - A) Red, because sunsets are red - B) Blue, because the sky is blue - C) Green, because the human eye is most sensitive to green - D) They are all equal

10. A JPEG differs from a RAW file in that the JPEG: - A) Is the undeveloped negative with full latitude - B) Has all processing decisions (white balance, color, tone, sharpening, compression) already baked in - C) Is always larger than a RAW file - D) Cannot be shared or viewed

11. The single physical part that defines a DSLR and distinguishes it from a mirrorless camera is: - A) The sensor - B) The lens mount - C) An angled mirror that bounces light to an optical viewfinder and flips up at exposure - D) The battery

12. A key practical advantage of a mirrorless camera over a DSLR is that it can: - A) Use no lens - B) Preview exposure, white balance, and depth of field on its electronic finder/screen before you shoot - C) Take photos without a sensor - D) Avoid needing light

13. The most common technical flaw in a beginner's photographs — a soft blur that isn't a focus error — is usually: - A) Too many megapixels - B) Camera shake from an unsteady hold during the exposure - C) The wrong brand of camera - D) A small sensor

14. On the mode dial, A (or Av) means you set the aperture and the camera sets the shutter. This mode is most useful when your priority is: - A) Controlling how motion blurs - B) Controlling depth of field (how much is in focus) - C) Maximizing megapixels - D) Turning off the sensor

True / False (justify every answer in one sentence)

15. True or False: More megapixels always means a better-quality photograph.

16. True or False: Moving a softbox or window closer to a subject makes its light softer — and this is related to why a large, near light source behaves differently from a small, distant one.

17. True or False: If your camera can only shoot JPEG, a badly blown-out (pure white) sky can reliably be recovered later in editing.

18. True or False: A camera with an optical viewfinder (a DSLR) shows you the scene's exposure and white balance before you press the shutter, just like a mirrorless electronic viewfinder.

19. True or False: Digital zoom on a phone gathers more real detail from a distant subject than simply cropping the same photo later would.

20. True or False: The aperture and the shutter, two of a camera's core parts, are also two of the controls you'll use to set exposure.

Short answer

21. In two or three sentences, explain why sensor size matters more than megapixel count for image quality. Use the word "photosite" and the idea of collecting light.

22. Name two situations in which you'd choose to shoot RAW instead of JPEG, and state one specific thing RAW preserves that JPEG discards.

23. A friend asks whether they should buy a DSLR or a mirrorless camera. Instead of answering directly, name two use-based questions you'd ask them first, and explain why the use should decide the type.

What's wrong here? (diagnostic / seeing)

24. A reader describes their setup: "I want maximum background blur for a portrait, so I bought the phone with the most megapixels (108 MP) and I'm zooming in with the phone's digital zoom to get closer." Identify the two conceptual mistakes in this plan and state what they should do instead.

25. A reader reports: "I shot a concert in a dark venue on JPEG at a very high ISO, handheld with one hand, zoomed all the way in. The photos are noisy, slightly blurry, and the colors look off — and I can't fix any of it." Diagnose at least three distinct causes from this chapter and prescribe a fix for each.

Answer Key

Click to reveal answers, explanations, and a topics-to-review map **1. B** — The core parts are the light-tight box, aperture, shutter, and sensor, plus a lens and a processor. (*Review §2.1*) **2. B** — A smaller hole passes fewer, more-aligned rays: dimmer but sharper. This previews the aperture trade-off. (*Review §2.1*) **3. C** — A lens breaks the pinhole's brightness-vs-sharpness trade by gathering lots of light *and* focusing it sharply. (*Review §2.2*) **4. B** — Short focal length = wide angle of view: more of the scene, things smaller and farther apart. (*Review §2.2*) **5. B** — Optical zoom changes the actual focal length and captures real detail; digital zoom crops into the existing image and enlarges it. (*Review §2.2*) **6. B** — A photosite is a single light-collecting well that counts the light at its spot; a *pixel* is the final image dot it produces. (*Review §2.3*) **7. C** — Same megapixels but larger sensor means larger photosites, each collecting more light → better signal-to-noise → cleaner low-light images. (*Review §2.3*) **8. C** — The Bayer color-filter array lets each photosite measure one color; demosaicing reconstructs the missing two at every pixel. (*Review §2.4*) **9. C** — Green is doubled because human vision is most sensitive to green, so green carries most of the luminance detail. (*Review §2.4*) **10. B** — A JPEG has all processing baked in and is compressed; a RAW file is the undeveloped negative with full latitude. (A is RAW; C is false — RAW is larger; D is false.) (*Review §2.4*) **11. C** — The angled mirror and optical viewfinder define a DSLR; removing the mirror makes a camera "mirrorless." (*Review §2.5*) **12. B** — Viewing the sensor's live signal lets a mirrorless camera preview exposure, white balance, and depth of field before the shot. (*Review §2.5*) **13. B** — Camera shake (an unsteady hold during the exposure) is the most common non-focus blur, and it's fixable for free by bracing. (*Review §2.6*) **14. B** — Aperture priority is for when depth of field is your priority; the camera handles the matching shutter. (*Review §2.6; depth of field is Chapter 4*) **15. False** — Past "enough" (~12 MP), more megapixels add resolution but not quality; sensor size and photosite size drive low-light cleanliness and tonal smoothness. (*Review §2.3*) **16. True** — Nearness makes a source *larger relative to the subject*, widening the soft shadow fringe (penumbra), so the light softens. Same geometry that makes a small distant source give hard shadows. (*Review §2.3 Physics box; light is Chapter 5*) **17. False** — A blown-to-pure-white sky in a JPEG usually has no recorded data to recover; the information is genuinely gone. RAW would have held more highlight latitude. (*Review §2.4*) **18. False** — An optical viewfinder shows the *real scene* directly through the lens, with no preview of the camera's exposure or white balance decisions; only an electronic finder/screen previews those. (*Review §2.5*) **19. False** — Digital zoom just crops and enlarges in advance, discarding surrounding pixels; cropping the full photo later keeps the same detail *and* more flexibility. (*Review §2.2*) **20. True** — Aperture (how much light) and shutter (for how long) are both core parts *and* exposure controls; the camera's structure and its key settings are the same things. (*Review §2.1; exposure is Chapter 3*) **21.** *Model:* Megapixels count how many photosites/dots there are, which is resolution, not quality. A larger sensor makes each photosite physically larger, so each one collects more light during the exposure; more light per well means a stronger signal relative to noise, which the eye reads as cleaner, smoother images — especially in low light. (*Review §2.3*) **22.** *Model:* Choose RAW for (any two) high-contrast scenes like sunsets, backlit portraits, mixed-light interiors, or any photo you intend to edit seriously. RAW preserves the sensor's full tonal latitude and the ability to reset white balance and recover highlight/shadow detail after the fact — all of which a JPEG bakes in and largely discards. (*Review §2.4*) **23.** *Model:* Ask (any two) "How much weight will you carry every day?", "How important is shooting in the dark / distant subjects?", and "What's your real budget including lenses?" The use determines the type because a wildlife shooter, a discreet traveler, and a studio portraitist have different needs — and the right answer might even be a phone. The type is a difference in convenience and ceiling, not in whether the picture is good. (*Review §2.5*) **24.** *Two mistakes:* (1) Megapixels don't create background blur — blur (shallow depth of field) comes from aperture, sensor size, focal length, and subject distance, not resolution. (2) Digital zoom degrades the image by cropping-and-enlarging rather than gathering real detail. *Instead:* use a wide aperture / the phone's Portrait mode, get physically closer at a real lens step, and crop later if needed. (*Review §2.2, §2.3; depth of field is Chapter 4*) **25.** *At least three causes + fixes:* (a) *Noise* — very high ISO on a small sensor; fix by lowering ISO where possible, bracing for a slightly longer shutter, or accepting/managing it (Ch. 3) and using a bigger sensor in the dark if you have one. (b) *Blur* — handheld with one hand at a high zoom magnifies camera shake; fix by bracing with both hands against a wall/railing, exhaling, and not over-zooming. (c) *Off colors you can't fix* — JPEG baked in a wrong white balance under stage lighting; fix by shooting RAW so white balance is resettable later. (d, bonus) *Lost detail from digital zoom*; fix by shooting at a real lens step and cropping later. (*Review §2.2, §2.3, §2.4, §2.6*) --- ### Topics to review, by question | If you missed… | Review | |---|---| | 1, 2, 20 | §2.1 — the light-tight box, aperture, shutter, sensor | | 3, 4, 5, 19, 24 | §2.2 — the lens, focal length, optical vs. digital zoom | | 6, 7, 15, 21 | §2.3 — sensors, photosites, size vs. megapixels | | 8, 9, 10, 17, 22, 25 | §2.4 — Bayer array, demosaicing, the pipeline, RAW vs. JPEG | | 11, 12, 18, 23 | §2.5 — phone vs. mirrorless vs. DSLR | | 13, 14, 25 | §2.6 — holding, focus, the controls and mode dial | | 16 | §2.3 Physics box (and forward to Chapter 5, light) |