Push processing allows analog photographers to shoot film in low-light environments beyond box speed rating by deliberately underexposing and compensating in the chemical developer.
1. Push vs. Pull Processing Characteristics
| Processing Technique | In-Camera Exposure | Chemical Development Adjustment | Visual Impact on Final Negative |
|---|---|---|---|
| Standard Box Speed (N) | Rated ISO (e.g. ISO 400) | Standard manufacturer development time | Balanced tonal range, nominal grain size |
| Push Processing (N+1 / N+2) | Underexposed by 1–2 stops (EI 800 / 1600) | Extended development time (+30% to +75%) | Steeper contrast, deeper blacks, increased grain size |
| Pull Processing (N-1 / N-2) | Overexposed by 1–2 stops (EI 200 / 100) | Reduced development time (-20% to -40%) | Flatter contrast, compressed dynamic range, ultra-fine grain |