Chapter 4 — Exercises

Focus is learned at the lens, not on the page, so most of these put a camera in your hands and ask you to control what is sharp and what dissolves. A phone is welcome everywhere — where a setting (aperture, manual focus) is hidden on phones, the exercise gives you a phone path. Difficulty is marked ⭐ (warm-up), ⭐⭐ (core), ⭐⭐⭐ (stretch). Do the starred and odd-numbered ones at minimum; model answers and critiques for those live in the book's Answers to Selected Exercises. Keep what you shoot — your shallow-focus keeper feeds the Portfolio.

Part A — Seeing focus (Read the Frame)

Exercise 4.1 ⭐ — Name the sharp thing. Find five photographs around you (your camera roll, a magazine, packaging). For each, write one sentence naming (a) what is sharp, (b) what is soft, and (c) what the focus choice tells you the photo is about. The goal is to start reading focus as emphasis.

Exercise 4.2 ⭐⭐ — Shallow or deep, and why. For three images you admire, decide whether each uses shallow or deep depth of field and write one sentence on why that was the right storytelling choice for that subject. Force yourself to find one of each.

Exercise 4.3 ⭐⭐ — Read This Frame: critique Figure 4.3. Re-read the Described Photograph "Coffee, isolated" (Figure 4.3 in the chapter). In your own words, name the three levers the photographer stacked to dissolve the background, and identify one change that would have made the background less dissolved. Then say what the image would lose if it were shot at f/16 instead.

Exercise 4.4 ⭐⭐⭐ — Reverse-engineer the depth of field. Find three photographs (yours or others') and, for each, deduce from the image alone: was the aperture wide or narrow? Was the photographer close or far? Long lens or wide? Defend each guess from visible evidence — the amount and character of background blur, the apparent subject distance, any compression. You are learning to read the three levers backward from their effects.

Part B — The three levers (Settings Drill & Shoot This)

Exercise 4.5 ⭐ — One lever at a time: aperture. Put a subject on a table with the room stretching behind it. Holding your position and focal length fixed, shoot it at your widest aperture, then at f/5.6, then at f/11 (phone: use pro/manual mode if you have it, or note that you cannot change this — and say why that matters). Lay the three side by side and describe how the background changed. Change only the aperture.

Exercise 4.6 ⭐⭐ — One lever at a time: distance. Same subject, same widest aperture, same focal length. Now shoot it from 0.5 m, then 1.5 m, then 4 m, recomposing so the subject stays a similar size if you can. Describe how depth of field changed with distance alone. (This is the lever beginners most underuse.)

Exercise 4.7 ⭐⭐ — One lever at a time: focal length. Same subject, same aperture. If you have a zoom or multiple lenses, shoot it at your widest focal length and at your longest, moving so the subject stays the same size in the frame. Compare the background blur. (Phone: use your main lens and your telephoto lens if you have one.) Which lens dissolved the background more?

Exercise 4.8 ⭐⭐⭐ — The three-lever experiment (full). Do the in-chapter §4.2 field assignment formally at your kitchen window: nine frames varying aperture, distance, and focal length deliberately, plus the phone variants (normal / Portrait / object-against-wall). Build a small contact sheet. Write one sentence per lever on what it did, and circle the single frame with the most dissolved background. Identify which lever contributed most.

Exercise 4.9 ⭐⭐ — Settings drill: isolate a face. You want a head-and-shoulders portrait with the eyes sharp and a busy street behind dissolved to color. Write the full starting recipe — mode, aperture, focal length, focus mode, AF area, where you place the focus point, and where you stand relative to subject and background — and explain the trade-off the wide aperture forces on shutter or ISO.

Exercise 4.10 ⭐⭐ — Settings drill: everything sharp. You are at a trail overlook with a flower a metre away and hills on the horizon, and you want both sharp. Write the full recipe (mode, aperture, where you focus, ISO, focus method, and whether you need a tripod) and justify why f/22 would be a mistake.

Part C — Autofocus and manual focus (Shoot This)

Exercise 4.11 ⭐ — Find your AF modes. Without shooting, open your camera's (or phone app's) menus and locate: single vs. continuous AF, the AF- area modes, eye/face detection, and (if present) back-button focus and manual-focus toggle. Write down what each is called on your gear. You cannot use a control you cannot find.

Exercise 4.12 ⭐⭐ — Single vs. continuous, proven. Have a friend (or pet) walk slowly toward you. Shoot a burst in AF-S (single), then a burst in AF-C (continuous). Inspect both at 100%. Note how many frames are sharp in each. This is the single most convincing demonstration of why mode choice matters.

Exercise 4.13 ⭐⭐ — Eye detection on and off. Shoot the same posed portrait twice: once with eye-detection AF on, once with a single center point and focus-and-recompose. At a wide aperture, compare how reliably the near eye is critically sharp. Keep the sharper one and say which method you trust.

Exercise 4.14 ⭐⭐⭐ — Focus where the camera won't. Find a subject behind an obstacle (flower behind a fence, candle behind glass, pet behind chair bars). Let autofocus try and fail; then focus manually (or with your phone's pro-mode focus slider), using focus peaking or magnified view if you have it, until the subject beyond is sharp. Keep the manual frame — a photo your autofocus could not make — and write what failed and what fixed it.

Exercise 4.15 ⭐⭐ — Back-button focus, one day. If your camera supports it, set up back-button focus (move focusing to the AF-ON button; remove it from the shutter). Shoot only this way for one full day. At the end, write three sentences on what changed: did recomposing get easier? Did you fire fewer hunting frames? Would you keep it? (Phone: instead, practice tap-and-hold AF/AE lock for the day and report the same.)

Exercise 4.16 ⭐⭐⭐ — Manual focus by feel, in the dark. After dark, photograph a single light source or a distant lit building where autofocus hunts. Switch to manual focus and set it by peaking or by racking to infinity. Get one sharp night frame autofocus refused to give you. Note the focus distance you settled on.

Part D — Selective focus as storytelling (Recreate It & Five Conditions)

Exercise 4.17 ⭐⭐ — Recreate "Coffee, isolated." Recreate the spirit of Figure 4.3 with your own object near a window: one clean subject, long lens (or phone telephoto), wide aperture, close in, with real distance and some bright points of light behind it so you get bokeh orbs. The challenge is restraint — one sharp thing, everything else dissolved.

Exercise 4.18 ⭐⭐ — Recreate "The vendor's hands." At a market or busy place (one of the four recurring locations), find a chaotic scene and use shallow focus to extract one sharp element (hands at work, a single face, an object changing hands) against a dissolved crowd. Observe consent — shoot people who are comfortable being photographed, or focus on gesture and hands rather than identifying faces (a thread we develop in Chapters 17 and 32). Find the photograph inside the chaos.

Exercise 4.19 ⭐⭐⭐ — One subject, five focus treatments (Five Conditions). Choose a single subject and photograph it five ways: (1) shallow DoF isolating it; (2) deep DoF with the whole scene sharp; (3) focus on the foreground, subject soft; (4) focus on the background, subject soft; (5) the hyperfocal/one-third approach. Self-select the best three and write why each works or fails as a statement, not just as a technical result.

Exercise 4.20 ⭐⭐ — Bokeh hunt. Find a scene with small bright points of light behind a subject (fairy lights, sun through leaves, distant streetlights). Shoot it at your widest aperture, focused close, so the background lights render as soft orbs. Describe the character of your bokeh — smooth and round, or busy and edged? Tie it to your lens.

Exercise 4.21 ⭐⭐⭐ — The hyperfocal landscape. At your park or trail, do the §4.6 field assignment: shoot a near-foreground-plus-distant-background scene three ways (focus near, focus far, focus a third in at f/8–f/11). Prove to yourself the one-third frame holds the most front-to-back sharpness. Note where you focused on the keeper.

Part E — Fix the Photo (Diagnose & Prescribe)

Exercise 4.22 ⭐⭐ — Fix: the soft-eyed portrait. Described failed shot: a head-and-shoulders portrait at f/1.8; the subject's ear and shoulder are crisp but the eyes are slightly soft; the background is beautifully dissolved. Diagnose exactly what went wrong and prescribe the precise re-shoot (mode, AF setting, technique). Name the one rule that was broken.

Exercise 4.23 ⭐⭐ — Fix: the cluttered background that won't dissolve. Described failed shot: a portrait at f/2.8 with a longish lens, but the background — a brick wall just behind the subject's head — is still distractingly sharp and busy. The photographer keeps opening the aperture with no improvement. Diagnose the real problem (it is not the aperture) and prescribe the fix.

Exercise 4.24 ⭐⭐⭐ — Fix: the soft landscape. Described failed shot: a landscape at f/22, focused on the distant mountains; the mountains are sharp but the foreground rocks are soft, and the whole image looks slightly mushy even where it should be crisp. Diagnose two separate errors and prescribe a re-shoot that fixes both.

Exercise 4.25 ⭐⭐ — Fix: the action that came out blurry-soft. Described failed shot: a child running toward the camera, shot in AF-S (single) at f/5.6, 1/1000 s; the shutter was fast enough to freeze motion, yet the child is out of focus while the spot just behind them is sharp. Diagnose (it is not motion blur) and prescribe the mode change.

Part F — Eye training (no camera; from the Light Log habit)

Exercise 4.26 ⭐ — Spot the focal plane. Looking only with your eyes (no camera), pick any scene and decide: if you focused on the nearest object, roughly how much in front of and behind it would stay sharp? Now imagine focusing on the farthest object. Narrate where the sharp band would fall in each case. You are training to see depth of field before you shoot.

Exercise 4.27 ⭐⭐ — Predict the blur. For three real scenes today, predict before raising any camera whether a wide-aperture shot would dissolve the background well — based on subject distance, background distance, and the lens you would use. Then (if you have a camera) test one. How good is your prediction getting?

Exercise 4.28 ⭐⭐ — Where would you put the sharpness? Watch people and scenes for ten minutes and, for five of them, decide silently: if this were a photograph, what single thing should be sharp, and should the rest dissolve or stay sharp? This is the storytelling decision of §4.5 practiced without a shutter.

Part G — Interleaved (mixing earlier chapters)

Exercise 4.29 ⭐⭐ — Focus and light (Ch. 1, 5 preview). Shoot a shallow-DoF object portrait twice: once in flat front light, once turned so soft light rakes across it from the side (the §1.4 lesson). Keep the version where good focus and good light combine. Which decision — focus or light — did more for the image?

Exercise 4.30 ⭐⭐ — Focus and exposure (Ch. 3). Set up a wide-aperture portrait and write the full exposure as a triangle: pick the aperture for depth of field first, then solve shutter and ISO for correct brightness in your actual light. Shoot it. Confirm the histogram is well-placed (Ch. 3) and the eye is sharp. Two controls, one frame.

Exercise 4.31 ⭐⭐⭐ — The camera, explained (Ch. 2). Using one of your own shallow-DoF frames as evidence, explain to someone why a bigger sensor would dissolve the background more than a phone for the same shot — and why the phone's deep depth of field is sometimes an advantage. Teaching forces clarity (Ch. 2's sensor lesson made real).

Exercise 4.32 ⭐⭐ — Settings drill, interleaved: the dim indoor candid. A friend is reading by a window in dim light; you want the eyes sharp and a soft background, but the light is low. Write the full decision chain: aperture (for DoF), ISO (for the dim light), shutter (fast enough for a hand-held person), AF mode and area. State the trade-off you are forced to accept and why it is the right one.

Stretch challenge

Exercise 4.33 ⭐⭐⭐ — One subject, the full range of sharpness, in one sitting. Pick a single subject with a foreground, a midground, and a background (a tabletop scene works, or a garden corner). In one sitting, make a deliberate set: maximum isolation (one element sharp, all else gone); maximum front-to-back sharpness (everything crisp); and three intermediate treatments that each emphasize a different element by where you place the focal plane. Lay all five out. You should be able to point at any one and say exactly which lever combination produced it — and what each says. This is depth-of-field mastery in a single afternoon.

Model answers and critiques for the starred and odd-numbered exercises appear in the book's "Answers to Selected Exercises." Try each with a camera before reading them — in photography, the attempt is the lesson, and a missed-focus frame teaches more than a paragraph.