| Distance | Very Close (VC) | Close (CC) | Far (FF) | Very Far (VF) |
| Less than 20 mm | 1 | 0 | 0 | 0 |
| 30 mm | 0 | 1 | 0 | 0 |
| 50 mm | 0 | 0 | 1 | 0 |
| Farther than 50 mm | 0 | 0 | 0 | 1 |