1. Focus On how to get a sharp picture

2. Outline Focus mechanism Focus type Focus drive Final notes

3. Focus mechanism Sensor o Phase detection o Contrast measurement Control system Motor o Internal o external

4. Focus type Manual Auto o Single point o Auto point detection Caution: Not all lenses are all-time focus

5. Focus drive Single shot (AF-S) Al-servo (AF-C) Al-focus (AF-A)

6. Final notes DEPTH and DIFFICULTY of Focus: DOF Hyper focal distance Sharpness is not only dependent on the focus o Shutter speed o Lens quality at different appertures