| focus | 0.34 |
| become shallower | 0.48 |
| depend on aperture | 0.34 |
| refer to the distance | 0.33 |
| become small | 0.33 |
| generate + 1st-order | 0.31 |
| extend 2/3 | 0.29 |
| depend on focal length | 0.28 |
| blur the background | 0.25 |
| extend to infinity | 0.25 |
| depend on subject dista… | 0.25 |
| the region | 0.38 |
| limited | 0.50 |
| increased | 0.39 |
| required | 0.37 |
| reduced | 0.34 |
| achieved | 0.33 |
| controlled | 0.31 |
| generated | 0.28 |
| magnified | 0.25 |
| determined | 0.25 |
| set | 0.25 |