A shoulder was imaged using 300 mA, 7 ms, 70 kVp, 40-inch SID, 1.2-mm focal spot, and 100 speed screen/film combination. Which of the following changes, made to compensate for changes in optical density, would result in decreased production/visualization of blur?
1. Use of a 0.6-mm focal spot
2. Use of a 50-inch SID
3. Screens with higher intensification factor