Chapter 19 — Self-Check Quiz

Twenty-eight questions to confirm you own the concepts before you go shoot. Mix of multiple choice, true/false-with-justification, short answer, and a few "what's wrong with this shot?" seeing questions. Answer without scrolling; the key and a one-line explanation for each are at the end, along with a "what to review" map. (Questions are grouped by type, so the numbering runs 1–15 and 26–28 for multiple choice, then 16–25 for the written questions — answer them in whatever order you like.)

Multiple choice

Q1. A 12mm subject projects a 6mm image on your sensor. What is the reproduction ratio? - A) 2:1 - B) 1:1 - C) 1:2 - D) 1:4

Q2. By the traditional definition, "true macro" begins at a reproduction ratio of: - A) 1:10 - B) 1:2 - C) 1:1 - D) 4:1

Q3. Up close, the depth-of-field lever that dominates — the reason your sharp zone is only a millimetre or two — is: - A) Aperture - B) Focus distance - C) Focal length - D) ISO

Q4. You stop a macro lens down from f/11 to f/22 hoping for more depth and the whole image gets softer. The cause is: - A) Camera shake - B) Missed focus - C) Diffraction - D) A dirty lens

Q5. Working distance is best defined as: - A) The distance from the sensor to the subject - B) The distance from the front of the lens to the subject at your chosen magnification - C) The minimum focus distance printed on the lens - D) The hyperfocal distance

Q6. You need to photograph a live, skittish dragonfly. Of two macro lenses that both reach 1:1, you should choose the longer (≈180mm) one mainly because it gives more: - A) Sharpness - B) Working distance - C) Magnification - D) Light

Q7. An extension tube increases magnification by: - A) Adding a magnifying glass element to the front of the lens - B) Moving the lens physically farther from the sensor - C) Cropping the sensor - D) Reversing the optical path

Q8. Which cheap path adds no glass and therefore no optical degradation of its own? - A) Close-up diopter - B) Extension tube - C) Teleconverter - D) Ring light

Q9. A ring light around the lens is excellent at one thing and weak at another. It: - A) Banishes the lens-shadow but produces flat, frontal light - B) Produces dramatic side light but casts a harsh shadow - C) Increases working distance but loses light - D) Softens hard light but darkens the frame

Q10. Focus stacking lets you keep shooting at a sharp aperture like f/8 instead of f/22 because: - A) f/8 has more depth of field than f/22 - B) depth comes from merging many frames, so each frame can use the lens's sharpest aperture - C) f/8 lets in more light - D) stacking only works wide open

Q11. Which subject is the worst candidate for focus stacking? - A) A dried leaf on a tabletop - B) An antique coin - C) A live butterfly on a flower - D) A seashell

Q12. A phone is naturally decent at macro depth of field mainly because: - A) its lens is very long - B) its sensor is very small, giving more depth of field at a given framing - C) it has a large aperture - D) it uses focus stacking automatically

Q13. The recommended single-frame aperture ceiling on a full-frame macro setup — beyond which diffraction costs you more than depth gains you — is around: - A) f/2.8 - B) f/5.6 - C) f/11 - D) f/45

Q14. Reversing a cheap wide-angle prime on a reversing ring is prized for delivering: - A) the longest working distance - B) extreme magnification well past 1:1 for almost no money - C) the best autofocus - D) the softest light

Q15. To get a flat coin sharp from edge to edge in a single f/8 frame, you should: - A) shoot it at a 45° angle - B) keep the sensor parallel to the coin's face - C) open up to f/2.8 - D) increase ISO

Q26. At true 1:1 on a full-frame camera, roughly how wide a patch of the real world fills the frame's long edge? - A) About 36 mm - B) About 36 cm - C) About 3.6 mm - D) About 1 metre

Q27. You're focusing at high magnification and autofocus keeps hunting and racking past your subject. The recommended technique is to: - A) switch to a smaller aperture - B) set the magnification, then rock your whole body forward and back to find focus - C) increase the shutter speed - D) use face-detection autofocus

Q28. A ring light is aimed at a small beetle and the shell looks flat and lifeless, though there's no shadow. The best fix to restore a sense of form is to: - A) move the ring light closer - B) raise the ISO - C) replace it with a diffused source from the side, plus a white card for fill - D) stop down to f/22

True / False — and say why

For each, mark T or F and add one sentence of justification.

Q16. "Cropping hard into a distant shot gives you the same real detail as shooting at true 1:1."

Q17. "At macro distances, the focus ring is so sensitive that rocking your whole body forward and back is often a more precise way to focus than twisting the ring."

Q18. "Soft light requires expensive modifiers; you can't make soft light for a tiny subject with a sheet of paper."

Q19. "At very short working distance, the front of your own lens can cast a shadow on the subject."

Q20. "A focus stack will still merge cleanly even if the subject moves a little between frames."

Short answer

Q21. In one or two sentences, explain why depth of field collapses to a sliver in macro even at a small aperture — name the lever responsible.

Q22. Describe the single most important move for getting soft light onto a small subject without your lens casting a shadow on it.

Q23. You own a 50mm prime and $15. Name the best purchase to start shooting macro and state, in one clause, why it doesn't hurt image quality.

What's wrong with this shot? (seeing questions)

Q24. A reader shows you a macro of a beetle: "I shot it at f/29 so everything would be sharp, with the pop-up flash firing straight at it. The whole frame looks soft and low-contrast, the shell looks flat, and there's a hard black shadow right behind the beetle." Name the three distinct problems and the fix for each.

Q25. A reader's focus-stacked flower came out "ghosted, with doubled, blurry edges instead of one sharp flower." Give the two most likely causes and how to prevent each next time.

Answer Key

Q1 — C (1:2). Subject 12mm → image 6mm is half life-size, written subject:sensor as 12:6 = 2:1 in size reduction, expressed as the ratio 1:2 (the image is half the subject). [§19.1]

Q2 — C (1:1). True macro is life-size on the sensor or greater, ≥1:1. Below that is "close-up." [§19.1]

Q3 — B (Focus distance). Focusing extremely close is what collapses depth of field; aperture only nibbles at the edges. [§19.2]

Q4 — C (Diffraction). Past the diffraction limit, light bending around the tiny aperture softens the entire image, not just the blurred parts. [§19.2]

Q5 — B. Working distance is lens-front to subject at your magnification — what your hand and your subject feel — distinct from focus distance (measured from the sensor). [§19.3]

Q6 — B (Working distance). The longer lens reaches 1:1 from much farther away, so you can stay back and not spook the insect, and have room to light it. [§19.3]

Q7 — B. A tube is a hollow spacer with no glass; it pushes the lens farther from the sensor so it focuses closer and magnifies more. [§19.3]

Q8 — B (Extension tube). No glass = no optical penalty of its own; you're just using your existing lens at a closer range. [§19.3]

Q9 — A. A ring light surrounds the lens so it removes the barrel-shadow, but its on-axis, frontal character flattens form — like any straight-on light. [§19.4]

Q10 — B. Stacking builds depth by merging many frames, so each individual frame can be shot at the lens's sharpest, diffraction-free aperture. [§19.5]

Q11 — C (live butterfly). Stacking needs a perfectly still subject; a butterfly moves between frames and the stack won't align. [§19.5]

Q12 — B. A tiny sensor yields much more depth of field at a given framing — exactly the resource macro is starved for. [§19.3]

Q13 — C (f/11). On full-frame, ~f/11 is the practical ceiling for a single macro frame before diffraction dominates; smaller sensors hit it at wider apertures. [§19.2]

Q14 — B. A reversed wide prime projects a small subject onto the sensor at high magnification — extreme ratios for the price of a reversing ring. [§19.3]

Q15 — B. Keeping the sensor parallel to the flat subject puts the whole face inside the thin slice at once — "free depth of field." [§19.2]

Q26 — A (about 36 mm). At 1:1 the subject is rendered life-size on the sensor, so a full-frame sensor's 36 mm long edge sees a 36 mm-wide strip of the world — the whole "scene" is a patch the width of a couple of fingernails. This is why subtraction and a clean background are so easy and so vital up close. [§19.1]

Q27 — B. At high magnification the focus ring is so sensitive it overshoots; the reliable technique is to fix the magnification and rock your body forward and back, firing the instant the subject snaps sharp. [§19.2]

Q28 — C. The ring light's flatness is the problem (on-axis light kills form); a diffused source from the side with a fill card restores the gradient of light-to-shadow that makes the shell look three-dimensional. [§19.4]

Q16 — False. Magnification is recorded detail; the distant shot recorded the subject with few photosites and then stretched them, while true 1:1 projects fine detail large onto the sensor. [§19.1]

Q17 — True. At high magnification the ring overshoots focus with the slightest turn; rocking the torso gives finer, more controllable adjustment of the plane. [§19.2]

Q18 — False. Soft means large relative to the subject; a tiny subject makes even a sheet of paper an enormous, soft source. [§19.4]

Q19 — True. At short working distance the barrel sits between the light (if it comes from behind the camera) and the subject, dropping a shadow on it — solved by bringing light forward and to the side. [§19.4]

Q20 — False. The subject must hold still between frames; movement causes misalignment, ghosting, and doubled edges in the merge. [§19.5]

Q21. Depth of field shrinks dramatically as focus distance gets very short, and macro focuses extremely close; aperture is only a secondary lever, so even a small aperture leaves you with a sliver. [§19.2]

Q22. Bring the (diffused) light forward and to the side, past the front of the lens, so it reaches the subject around the barrel rather than being blocked by it; a white card opposite fills the shadow. [§19.4]

Q23. A set of extension tubes — they contain no glass (they just move the lens farther from the sensor), so they add no optical degradation of their own. [§19.3]

Q24 — three problems: (1) f/29 → diffraction: the whole frame is soft because you've gone far past the diffraction limit — fix: shoot at f/8–f/11 and focus-stack if you need more depth. (2) On-axis pop-up flash → flat shell: straight-on light kills form — fix: use a diffused source from the side with a fill card. (3) Bare hard flash → hard black shadow: undiffused tiny source — fix: diffuse it (sandwich bag/vellum) and move it off-axis. [§19.2, §19.4]

Q25 — two likely causes: (1) The subject moved between frames (a flower outdoors sways in the faintest breeze) — prevent by shooting indoors, still air, locked-down tripod. (2) The exposure or framing changed frame to frame — prevent with manual mode, fixed white balance, a remote/timer, and a rigid tripod so every frame matches. (A third: too few frames leaving gaps — overlap generously.) [§19.5]

What to review, by question

If three or more answers came from one section, reread that section before the Portfolio Checkpoint — and then go prove it at arm's reach. Everything in this chapter is verified by shooting, not by remembering.