Overview
This guide uses Selection Logic so you can choose by need and evidence. Key traps: megapixel myth; phone vs camera decision; lens-system lock-in.
Theory anchor: T1 Matching Theorem—good choices match your needs, not "objectively best" configs.
Step 1 → Need clarification (M1)
Use M1 Need Clarification to define real usage and constraints.
Scenario analysis
| Scenario | Primary considerations |
|---|---|
| Portrait & street | AF, focal length, portability |
| Landscape & travel | wide angle, stabilization, battery, weight |
| Video / vlog | AF, stabilization, codec, ports |
| Pro & commercial | resolution, color, lens ecosystem |
Example need list
- Must-have: key metrics for main scenario
- Nice-to-have: experience and convenience
- Bonus: support, brand, expansion
Step 2 → Allocate cognitive budget (T2)
These products are typically medium-to-high value and low reversibility. Use T2 Cognitive Budget and Decision Reversibility to allocate time.
Suggested time: need clarification 30 min; evidence gathering 2–2 h; comparison 1 h.
Step 3 → Multi-dimensional evaluation (M2)
Use M2 Multi-Dimensional Evaluation. In this guide, stress: Stress: megapixel myth—sensor size and lenses matter as much; phone vs camera—decide by use case and output needs; lens-system lock-in—choosing a system commits you to its lens ecosystem.
Evaluation dimensions
| Dimension | Sub-items | Evidence sources |
|---|---|---|
| Image quality | sensor size, megapixels, ISO, DR | reviews, samples |
| AF & stabilization | AF speed, tracking, IBIS | tests, reviews |
| Lens ecosystem | focal range, price, weight | system comparison |
| Video & battery | codec, ports, battery | specs, reviews |
Weight example
Per T1, set weights by your needs, e.g. Image quality 30%%; AF & stabilization 25%%; lens ecosystem 30%%; video & battery 15%%.
Step 4 → Bias & persuasion hazards
- Anchoring effect: don't anchor on high-end prices; fix budget and needs first.
- Confirmation bias: write criteria before browsing; avoid justifying a favorite.
- Halo effect: brand and marketing carry value assumptions—see T1.2.
- Specs and claims: rely on measurements and third-party data; beware claimed vs actual.
Step 5 → Decision + validation (M5)
Apply M5 Decision Validation.
Checklist: core needs met (fit score); within budget; satisficing threshold (T4.2); still satisfied after cooling-off.
Post-purchase: Need consistency—after 1–3 weeks, check real usage vs expectations, key metrics, regret points.