Chapter 25 — Exercises

Mobile editing is learned by editing, so most of these put a finished or half-finished file in front of you and ask you to develop it on your phone. Use the developer app you chose in §25.1 throughout — depth in one app beats dabbling in ten. Difficulty is marked ⭐ (warm-up), ⭐⭐ (core), ⭐⭐⭐ (stretch). Do the starred and odd-numbered ones at minimum; model answers and critiques for those are in the book's Answers to Selected Exercises. Keep your edits non-destructive and keep your originals — several of these feed your Portfolio, and one becomes the desktop comparison in Chapter 26.

Part A — The toolkit and the workflow (Settings Drill & Recall)

Exercise 25.1 ⭐ — Sort your apps. Open your phone and list every photo app you have. Sort each into one of the four categories from Figure 25.1: camera, developer, specialist, or publisher. Then answer: which one developer will be your main workbench, and does it pass the three tests (accepts RAW, true local adjustments, saves your own presets)? If it fails any, name a free or low-cost developer that passes.

Exercise 25.2 ⭐ — Write the order from memory. Without looking at Figure 25.2, write down the seven steps of the global develop order, in sequence, and the one-line decision each step is making. Then check yourself. The two laws — "global before local," "tone before color" — should fall out of the order naturally; explain why each is true.

Exercise 25.3 ⭐⭐ — The destructive-app trap. Find (or recall) an app that opens a photo, lets you apply a filter, and saves over the original with no way to dial it back later. In a short paragraph, explain exactly what "non-destructive" means, why that app violates it, and what you lose the day you decide a filter you applied six months ago was too strong.

Exercise 25.4 ⭐⭐⭐ — Map the publisher's interference. Pick one platform you post to (Instagram, a messaging app, a website host). Post a test image you've already sized correctly, then save the version the platform displays back and compare it to what you uploaded, pixel for pixel. Document what the publisher did to it — re-compression, resize, crop, color shift. This is the hidden fourth editor in action; knowing its habits is how you defend against them in §25.5.

Part B — The RAW develop pass (Shoot This & Settings Drill)

Exercise 25.5 ⭐ — RAW vs. JPEG, your own proof. Shoot one high-contrast scene (a window-lit room looking out to a bright exterior is ideal) twice on your phone: once as a normal JPEG, once as RAW. Develop only the RAW, recovering detail in the brightest and darkest areas. Lay the two finished images side by side and write one sentence on the single biggest difference. Keep both, labeled, as permanent evidence.

Exercise 25.6 ⭐⭐ — Develop one RAW in strict order. Take any RAW file and develop it walking the seven steps of Figure 25.2 in order, once, without backtracking (you may revisit afterward). After each step, note what you changed and why. The discipline of the order is the lesson; resist jumping ahead to saturation.

Exercise 25.7 ⭐⭐ — Vibrance vs. Saturation, head to head. Take one colorful RAW with a person or a vivid sky in it. Make two versions: one where you push Saturation to taste, one where you push Vibrance to taste. Compare what happens to skin tones and to the already-vivid colors. Write which you'd keep and why. This is the §25.2 common-mistake made tactile.

Exercise 25.8 ⭐⭐⭐ — Recover the un-recoverable. Deliberately shoot a scene where the sky is badly overexposed — once as JPEG, once as RAW. Try to recover the sky's cloud detail in each. Document where the JPEG gives up (the sky stays a flat white patch) and how far the RAW lets you push before it, too, breaks. You're learning the limits of latitude, not just its existence.

Exercise 25.9 ⭐⭐ — White balance as mood, not just correction. Take one RAW shot in warm late-day light. Make three versions: a "technically neutral" white balance, a "keep the warmth" version, and a deliberately cool version. Decide which best serves the photograph and defend it in a sentence. White balance is a creative choice, not only a correction (Chapter 5).

Part C — Local adjustments (Shoot This & Read the Frame)

Exercise 25.10 ⭐ — Spotlight the subject. Take any developed image with a clear subject. Add a radial mask over the subject and lift its exposure a third of a stop; then invert a copy and darken everything outside the subject instead. Compare the two approaches and the "no mask" original. Notice how little it takes to make the eye snap to the subject.

Exercise 25.11 ⭐⭐ — The graduated sky. Find or shoot a landscape with a too-bright sky. Use a linear/graduated mask to pull the sky down about a stop while leaving the land untouched, fading the effect to nothing at the horizon. This is the digital graduated ND from Chapter 16. The test of success: a viewer can't find the seam.

Exercise 25.12 ⭐⭐ — Brush with restraint. Take a portrait or a photo of a person. Using the brush tool, zoom in and lift only the eyes by a small amount, and brush down one distracting bright patch elsewhere in the frame. Feather both. The challenge is invisibility — if the edit is obvious, it's too strong or unfeathered.

Exercise 25.13 ⭐⭐⭐ — Audit an AI mask. Use your developer's automatic "select sky" or "select subject" mask on a tricky image (hair against sky, foliage, a complex edge). Zoom into the boundary and find where the machine got it wrong. Fix the edge by hand (brush in/out). Write two sentences on where auto-masks can and can't be trusted. (We dissect why they fail in Chapter 23.)

Exercise 25.14 ⭐⭐ — Read the frame: name the local edits. Below is a Described Photograph. Identify, from the description alone, at least three local adjustments the editor must have made and which selection tool each likely used.

text "Lone hiker on a ridge" [constructed teaching example] A small figure stands on a rocky ridge against a bright sky. The figure is clearly the brightest, crispest thing in the frame and pops off the slope. The sky above is a rich graduated blue, darkest at the top edge, fading to pale at the ridgeline. A bright distracting boulder that would have sat in the lower-left corner is noticeably dimmer than its neighbors. The rest of the slope is soft and slightly darkened, funneling the eye up to the figure.

Part D — Presets and consistency

Exercise 25.15 ⭐ — Build your first preset. Develop one image until you genuinely love it, then save the whole recipe as a named preset ("Window Still Life," "Blue Hour," your choice). Apply it to a different image and observe what carries over well and what doesn't. Congratulations — you've started a personal palette.

Exercise 25.16 ⭐⭐ — The set that belongs together. Take five images from one shoot (same light, same place). Apply one preset to all five, then go through and hand-adjust each image's exposure so they match in brightness. Compare the set before and after the per-image exposure pass. Write one sentence on why the preset alone wasn't enough.

Exercise 25.17 ⭐⭐⭐ — Consistency, not sameness. Take three different kinds of image from one outing — say a portrait, a wide scene, and a detail. Edit all three to share a recognizable look (a through-line of color and contrast) while keeping each true to its own subject. The test: a viewer should feel they're "by the same hand" without the three looking identical. This is the editing half of personal style (Chapter 39).

Exercise 25.18 ⭐⭐ — The bought-preset reality check. If you own or can trial a purchased preset pack, apply one preset to three of your images and compare the result to the seller's marketing examples. Document the gap, and what you'd have to adjust by hand to close it. (If you own none, do this with a built-in preset instead.) Conclude: a preset is a starting point or a finish?

Part E — Export and publish (Settings Drill & Fix the Photo)

Exercise 25.19 ⭐ — Crop for four homes. Take one image and export it four times, cropped deliberately for four destinations: a 4:5 portrait feed post, a 1:1 square, a 9:16 vertical story, and a 3:2 print. For each, frame the crop on purpose so the subject survives the cut. Notice how differently you have to think for the tall 9:16 versus the wide 3:2.

Exercise 25.20 ⭐⭐ — The over-large upload test. Export one image at full resolution (say 6,000+ px) and again at ~2,048 px. Upload both to the same social platform and compare how each looks in the feed. Document which the platform handled better and why (re-compression of the giant file). Write the resolution you'll use for that platform from now on.

Exercise 25.21 ⭐⭐ — Sharpen for the destination. Take one finished image. Export it once with "screen" output sharpening and once with "print" output sharpening (use the strongest print/matte option). View the screen version on your phone and, if you can, get the print version printed (or zoom to 100% to judge edge crispness). Describe how each looks wrong in the other's context (screen-sharpened-but-printed = soft; print-sharpened-on-screen = crunchy).

Exercise 25.22 ⭐⭐⭐ — Fix the photo: diagnose the export failure. A friend says: "I edited this photo and it looked great in the app, but after I posted it it's soft and the top of someone's head got cut off, and the colors look slightly washed." Using §25.5, diagnose each of the three symptoms (soft / cropped / washed) to a specific export-or-publish cause, and prescribe the exact fix for each. You may not blame the app vaguely — name the setting.

Exercise 25.23 ⭐⭐ — Build your export checklist. Write your own personal export checklist (aspect ratio, resolution, format, output sharpening, and "keep the RAW + non-destructive master") for the three destinations you actually use most. Tape it inside your editing routine. This is the card you'll consult until it's automatic.

Part F — The complete edit (Shoot This)

Exercise 25.24 ⭐⭐ — The full pipeline, kitchen window. Run the entire §25.6 pipeline on one new capture: set an ordinary object by the kitchen window in soft raking light, shoot RAW, then import → global develop in order → at least two eye-directing local adjustments → deliberate crop → save a preset → export correctly for one destination → publish or place. Keep notes on every step. This is the chapter's core skill in one sitting.

Exercise 25.25 ⭐⭐⭐ — The bus-ride deadline. Give yourself a hard time limit (20–30 minutes) and a small batch: develop, locally adjust, preset-match, export, and post three RAW files from one shoot, as if you were turning around a same-day "selects" set on the move. Judge the result as a coherent set, not three separate images. Speed with the order is the professional skill here.

Exercise 25.26 ⭐⭐ — The Light Log: edit-light edition. Add today's Light Log entry, but with a twist: note one photo you've seen online whose edit you admire, and describe in words what the editor likely did — the color signature, the contrast, where the eye was directed locally. Reading edits backward (like reading light backward in Chapter 1) trains you to make them.

Part G — Interleaved (mixing prior chapters)

Exercise 25.27 ⭐⭐ — Expose right, edit less. Shoot the same scene twice on your phone: once exposed carelessly (let auto do whatever), once exposed deliberately to protect the highlights (Chapter 3 — "expose to keep detail in the bright areas"). Develop both to the same finished look. Document how much less editing the well-exposed capture needed. The darkroom rewards the photographer who got it right in the field.

Exercise 25.28 ⭐⭐⭐ — Mixed light, tamed in post. Find a scene with genuinely mixed light — warm bulbs and cool window, or the blue-hour street with sodium, neon, and fluorescent all at once (Chapter 15, Chapter 21). Shoot RAW, then use white balance plus per-color HSL to bring the clashing sources into a deliberate relationship. You can't fully "fix" mixed light, but you can resolve it in post far better with a RAW than a JPEG. Write what you couldn't fix and why.

Exercise 25.29 ⭐⭐ — Compose for the crop you'll export. Pick a destination before you shoot — say a 9:16 vertical story. Now go shoot three frames composed for that tall shape (Chapter 6), then develop and export them at 9:16. Notice how knowing the export shape changed how you framed in the field. Capture, edit, and audience are one decision.

Stretch challenge

Exercise 25.30 ⭐⭐⭐ — One RAW, two darkrooms (the Chapter 26 setup). Choose one strong RAW keeper. Develop it to a finished, exported state entirely on your phone this week, keeping meticulous notes on every adjustment. Save the finished file, the notes, and the untouched RAW together as 25-mobile-edit. Do not edit it on a computer yet. You are deliberately banking the mobile version so that in Chapter 26 you can re-develop the identical file on a desktop and compare — proving to yourself exactly how far the phone gets you, and where the big screen earns its place. This is your Portfolio Checkpoint and the most instructive exercise in the chapter.

Model answers and critiques for the starred and odd-numbered exercises appear in the book's "Answers to Selected Exercises." Edit each one before reading them — in the darkroom, the attempt is the lesson, and the histogram on your own file is the truest teacher.