Chapter 15 — Self-Check Quiz

Twenty-six questions to test whether the two-exposure model, dragging the shutter, gels, blue-hour fill, and mixed-light strategy have truly landed. A mix of multiple choice, true/false (with justification), short answer, and "what's wrong with this exposure?" seeing-questions. Answer everything before checking the key at the bottom. For true/false, you must justify — an unjustified guess earns nothing.

Multiple choice

Q1. In a flash photograph, which control primarily sets the brightness of the background/ambient? - A. Flash power - B. Shutter speed - C. The gel - D. Focus mode

Q2. Which control primarily sets the brightness of the flash-lit subject? - A. Shutter speed - B. ISO only - C. Flash power - D. White balance

Q3. A flash burst typically lasts about: - A. 1/30 of a second - B. 1/1000 of a second or faster - C. A full second - D. Exactly the sync speed

Q4. Electronic flash is, by design, balanced to roughly which color temperature? - A. ~2700 K (warm tungsten) - B. ~3200 K (warm) - C. ~5500 K (daylight/neutral) - D. ~9000 K (cool shade)

Q5. You are shooting in a warm, tungsten-lit room with a bare flash. To make the flash match the room, you should: - A. Put a CTB gel on the flash and set white balance to daylight - B. Put a CTO gel on the flash and set white balance to tungsten - C. Put a green gel on the flash and set white balance to daylight - D. Remove the flash entirely

Q6. "Dragging the shutter" means: - A. Using a shutter speed faster than the sync speed - B. Using a slow shutter speed together with flash - C. Dragging the camera physically across the scene with no flash - D. Lowering the flash power to its minimum

Q7. For a moving subject in a dragged-shutter shot, which sync mode makes the motion trail fall behind the subject (the natural-looking way)? - A. Front-curtain (first-curtain) sync - B. Rear-curtain (second-curtain) sync - C. High-speed sync - D. It makes no difference

Q8. At blue hour, which dial do you use to expose the sky? - A. Flash power - B. The gel - C. Shutter speed (with aperture/ISO) - D. Rear-curtain sync

Q9. As blue hour deepens and the sky gets darker, to keep the sky correctly exposed you should generally: - A. Raise the flash power - B. Slow the shutter speed - C. Speed up the shutter - D. Switch white balance to daylight

Q10. Which is the most controlled strategy for a multi-colored room when you have access to the lights? - A. Let auto white balance average it - B. Un-mix: gel/turn off lights so everything is one color - C. Always embrace the split - D. Use the on-camera flash bare

Q11. A CTO gel does what to your flash? - A. Cools it toward blue - B. Warms it toward tungsten/orange - C. Adds green - D. Reduces its power by one stop only

Q12. You set the ambient exposure correctly, then add flash and the subject is too bright. The single best fix is: - A. Slow the shutter - B. Open the aperture - C. Lower the flash power - D. Raise the ISO

Q13. In the ambient/flash balance spectrum, a fast shutter with a strong flash produces: - A. An ambient-dominant, natural-light look - B. A flash-dominant look with a dark/black background - C. A blurry mess - D. A perfectly balanced exposure every time

True / False — justify your answer

Q14. Shutter speed has almost no effect on the flash exposure. True or false? Justify.

Q15. A single white-balance setting can render two different colors of light both correctly at the same time. True or false? Justify.

Q16. You can use any shutter speed you like with a normal flash, including speeds faster than the sync speed. True or false? Justify.

Q17. At blue hour, the subject's face should be lit brighter than the sky so it stands out. True or false? Justify.

Q18. Gelling the flash without also changing the white balance fixes a color mismatch. True or false? Justify.

Q19. Shooting RAW lets you un-mix two different colors of light that are falling on the same part of the frame. True or false? Justify.

Short answer

Q20. In two or three sentences, explain the "two-exposure model" of flash photography to someone who has never heard it.

Q21. A photographer says, "My flash photos always have a black background and I hate it." Name the cause and the one-sentence fix.

Q22. Describe the order in which you should set the two exposures (ambient and flash) when starting a mixed-light shot, and give the reason for that order.

Q23. Name the three deliberate strategies for mixed light and give a one-line situation where each is the right choice.

Seeing questions — "what's wrong with this exposure?"

Q24. Diagnose this described frame.

An indoor portrait in a cozy, lamp-lit living room. The subject's face is clean and neutral-colored and nicely lit. But the entire room behind them — the warm lamps, the wood walls — has gone a strong, unnatural orange. The photographer used a bare flash and set white balance to daylight. What single mismatch caused the orange room, and what two paired steps fix it?

Q25. Diagnose this described frame.

A photo of a dancer under stage lights, shot at 1/4 s with flash. There's a nice motion streak — but it appears to run ahead of the dancer, as if she's moving backward, and it overlaps and muddies the sharp frozen image of her. What setting is wrong, and what should it be changed to?

Q26. Diagnose this described frame.

A dusk portrait. The sky is a gorgeous saturated blue and the horizon glows amber — beautiful. But the subject's face is so bright it looks cut out and pasted onto the scene, brighter than anything else in the frame, with a hard-edged shadow on the wall behind them. Name two things that are wrong (one about brightness, one about the quality of the flash) and how you'd fix each.

Answer Key

Reveal answers and explanations **Q1 — B.** Shutter speed is the ambient dial; the flash burst is too brief to be affected by shutter duration, so a longer shutter brightens the background without changing the flash. *(§15.1)* **Q2 — C.** Flash power sets the brightness of the flash-lit subject and does not affect the ambient. *(§15.1)* **Q3 — B.** A flash burst is typically 1/1000 s or faster — far shorter than a normal shutter time, which is exactly why shutter speed barely touches it. *(§15.1, §15.2)* **Q4 — C.** Electronic flash is daylight-balanced, ~5500 K — neutral, matching midday sun, not the warm indoor light it usually fires into. *(§15.3)* **Q5 — B.** Warm room → warm the flash with a **CTO** to match it, then set white balance to **tungsten** so both the matched flash and the room render naturally. *(§15.3)* **Q6 — B.** Dragging the shutter = a slow shutter speed combined with flash, so the slow shutter records ambient/motion while the flash freezes a sharp core. *(§15.2)* **Q7 — B.** Rear-curtain (second-curtain) sync fires the flash at the *end* of the exposure, so the streak is laid down first and the sharp freeze lands on top — trails fall behind the subject. *(§15.2)* **Q8 — C.** Shutter speed (with aperture and ISO) sets the ambient exposure, and the sky *is* the ambient at blue hour. *(§15.4)* **Q9 — B.** Slow the shutter to gather more light from the darkening sky, while the flash on the face stays put. *(§15.4)* **Q10 — B.** Un-mixing (gel/turn off lights until everything is one color) is the most controlled strategy when you have access to the lights. *(§15.5)* **Q11 — B.** CTO = Color Temperature Orange; it warms a daylight flash toward tungsten (~3200 K). *(§15.3)* **Q12 — C.** The subject is the flash-lit part, so lower the flash power — the dial that changes the subject without disturbing the background you already set. *(§15.1)* **Q13 — B.** Fast shutter (short ambient) + strong flash pushes the balance toward flash-dominant: the background goes dark/black and the subject floats in the flash's light. *(§15.1, §15.6)* **Q14 — True.** The flash burst (~1/1000 s) is over long before a normal shutter closes, so changing the shutter from, say, 1/200 s to 1 s lets in more *ambient* but leaves the flash contribution essentially unchanged. *(§15.1)* **Q15 — False.** White balance is a single global instruction — "treat *this* color as white." It can please only one light color; any second color is left with a cast. The remedy is to make both lights the same color (a gel), not to ask one white balance to do the impossible. *(§15.3, §15.5)* **Q16 — False.** Above the sync speed the shutter curtains form a moving slit and the sensor is never fully uncovered at once, so a single flash burst would light only a strip, leaving a black band. The sync speed (~1/200–1/250 s) is the fastest usable shutter with a normal flash. *(§15.2, Ch.11 §11.2)* **Q17 — False.** In the real world the sky is usually the brightest thing; a face brighter than the whole sky looks artificial/pasted-in. Light the face to sit *at or slightly below* the ambient level. *(§15.4)* **Q18 — False.** Gel and white balance are a pair. Gelling the flash warm but leaving white balance on daylight makes the subject *too warm and* the room still orange. You must gel to the room's color *and* set white balance to that same color. *(§15.3)* **Q19 — False.** RAW lets you fine-tune the *global* white balance (and brush local corrections in strong editors), but it cannot un-mix two different colors lighting the *same* spot — only a gel at capture does that. *(§15.3, §15.5)* **Q20.** *Model answer:* A flash photo is really two exposures in one frame — the ambient light already in the scene, and the burst from your flash. They add together but are controlled separately: shutter speed sets the ambient/background brightness, and flash power sets the subject brightness, so you can adjust each without disturbing the other. *(§15.1)* **Q21.** *Cause:* the camera (or the photographer) used a fast shutter, so the ambient exposure was too short to record the room, leaving the flash-lit subject on a black void. *Fix:* slow the shutter (take manual control) to let the ambient register the background. *(§15.1)* **Q22.** *Model answer:* Set the **ambient first**, with the flash off — aperture, shutter, ISO to expose the background the way you want (often a touch dark). *Then* turn the flash on and set its power for the subject. The reason: the ambient defines the world you're placing the subject into, so you want to know what background you're working against before you light the person. *(§15.1)* **Q23.** *Model answer:* **(1) Un-mix** — gel/turn off lights so everything is one color (best when you control the room; e.g., a studio-ish setup on location). **(2) Pick a winner** — set white balance for the subject's light and let the rest shift (best on location with no control; e.g., a face under warm lamps with a cool window behind). **(3) Embrace the split** — compose with the two colors, maybe exaggerate (best for a stylized look; e.g., a warm-gelled subject against a cold blue street). *(§15.5)* **Q24.** *Diagnosis:* the bare flash is daylight (~5500 K) but the room is warm tungsten (~3200 K); with white balance on daylight the flash-lit face is correct but the warm room is rendered too orange — a classic color mismatch. *Fix (paired):* (1) put a **CTO** gel on the flash to warm it to the room's color, and (2) set white balance to **tungsten** so both now render naturally. *(§15.3)* **Q25.** *Wrong setting:* the flash is on **front-curtain** sync, so it freezes the dancer at the *start* and the streak paints ahead of her (reads as moving backward). *Fix:* switch to **rear-curtain** sync so the streak is recorded first and the sharp freeze lands at the end, putting the trail behind her. *(§15.2)* **Q26.** *Two faults:* (1) **Brightness** — the flash power is too high; the face is brighter than the sky, which looks pasted-in. Fix: lower the flash power so the face sits at or just below the ambient sky level. (2) **Quality** — the hard-edged shadow on the wall means the flash is small/bare and hard (and probably too close to the wall). Fix: soften the flash (a small softbox, umbrella, or bounce — Chapter 12) and/or move the subject away from the wall so any shadow falls out of frame. *(§15.4; soft light recall Ch.5/Ch.12)*

Topics to review by question

  • Q1–Q3, Q12, Q13, Q14, Q20–Q22: the two-exposure model and ambient/flash balance — §15.1.
  • Q6, Q7, Q16, Q25: dragging the shutter, sync, front vs. rear curtain — §15.2 (and Ch.11 §11.2).
  • Q4, Q5, Q11, Q18, Q24: color temperature and gels (CTO/CTB) — §15.3.
  • Q8, Q9, Q17, Q26: blue-hour portraits with fill — §15.4.
  • Q10, Q15, Q19, Q23: mixed-light white-balance strategy and color casts — §15.5 (and §15.6).

If you missed more than two in any one band, reread that section and redo the matching exercises before your Portfolio shoot — mixed light punishes vague understanding and rewards the photographer who knows exactly which dial does what.