Phase vs Contrast-Detection AFequipment
Two ways cameras find focus — phase detection is fast and predictive; contrast detection is precise but slower.
Phase-detection autofocus measures how far and which way focus is off and drives the lens straight there, making it fast and strong at tracking motion. Contrast-detection hunts for maximum sharpness — very accurate but slower. Modern mirrorless cameras use on-sensor 'hybrid' AF that blends both, which is why their subject- and eye-tracking has become so good.
Use this when
- Tracking moving subjects: Phase detection
- Static, critical focus: Contrast detection
Common mistake: Blaming the lens for slow AF when it's the AF mode or low-light contrast at fault.