Push processing, or push developing, involves intentionally overdeveloping film to increase its effective ISO (sensitivity to light). This technique is a powerful tool for photographers shooting in low-light conditions or seeking a specific aesthetic, but it demands a firm understanding of the process. Successfully pushing black and white film at home hinges on carefully adjusting development times to compensate for underexposure, resulting in higher contrast and grain but often rescuing otherwise unusable images. This article will guide you through every step, ensuring you achieve professional-quality results from your own darkroom.
Understanding Push Processing: Why and When
Before diving into the how-to, it’s crucial to understand the why behind push processing. Film has a rated ISO, indicating its sensitivity to light. However, you might find yourself in a situation where there isn’t enough light available for a properly exposed image at that ISO and your desired aperture and shutter speed. Pushing film allows you to effectively trick the film into behaving as though it’s more sensitive to light.
- Shooting in Low Light: The most common reason for pushing film is to capture images in environments where there isn’t ample light. This might be indoors, during dusk or dawn, or in dimly lit streets.
- Freezing Action: By increasing the effective ISO, you can use faster shutter speeds to freeze motion in challenging lighting situations.
- Achieving a Specific Look: Push processing increases contrast and grain, which can be desirable for a particular artistic effect. This “gritty” aesthetic is often associated with photojournalism and documentary photography.
However, be aware of the drawbacks. Push processing always results in increased contrast and grain. Shadow detail may also be compromised. The degree of these effects depends on the amount of push and the specific film used.
The Essential Steps: A Comprehensive Guide
Step 1: Planning Your Shot and Metering
Before even loading your film, decide if push processing is necessary. Meter the scene carefully. Determine the correct exposure for the film’s rated ISO. Then, assess how much you need to underexpose the film to achieve your desired aperture and shutter speed. This determines the “stop push” you need (e.g., pushing one stop, two stops, etc.). Remember, one stop of underexposure doubles the development time roughly.
Step 2: Shooting and Underexposing the Film
Once you’ve decided on the push, deliberately underexpose the film according to your plan. For example, if you’re pushing one stop, set your camera one stop faster than your meter reading for the film’s rated ISO. If the film is rated at ISO 400 and you’re pushing to ISO 800 (one stop), meter as though the film were ISO 800. Accurate and consistent underexposure is crucial for consistent results.
Step 3: Preparing Your Development Materials
Gather your necessary equipment:
- Developer: Choose a developer known for its ability to handle push processing well. Popular choices include Ilford ID-11/Kodak D-76 (used interchangeably at their standard dilutions or at 1+1 for even more sharpness and contrast), Kodak HC-110, and Rodinal.
- Stop Bath: Diluted acetic acid or a commercial stop bath.
- Fixer: Rapid fixer is generally preferred for its efficiency.
- Wetting Agent: Essential for minimizing water spots.
- Measuring Cylinders: Accurate measurement is critical.
- Thermometer: Maintaining proper temperature is vital.
- Development Tank and Reels: Ensure your tank and reels are clean and dry.
- Timer: Use a timer with a second hand or a digital timer.
Step 4: Adjusting Development Time
This is the heart of push processing. Development time needs to be increased proportionally to the degree of push. There isn’t a single formula that works for all films and developers. Start with recommendations from the film or developer manufacturer, or consult online resources like the Massive Dev Chart (massive.darkroommagic.com). As a general guideline:
- One Stop Push: Increase development time by approximately 30-50%.
- Two Stop Push: Increase development time by approximately 50-100%.
- Three Stop Push: Increase development time by approximately 100-150%.
These are starting points. You will likely need to fine-tune your development times based on your specific film, developer, and desired results through experimentation. Keep detailed notes of your process to optimize future developments.
Step 5: Developing the Film
Follow your standard development procedure, but with the adjusted development time calculated in the previous step:
- Pre-wash: Fill the tank with water at the developer temperature. Agitate for one minute, then discard. This helps ensure even development.
- Developer: Pour in the developer at the correct temperature. Start your timer. Agitate continuously for the first 30 seconds, then agitate for 5-10 seconds every 30 seconds for the duration of the development time.
- Stop Bath: Pour out the developer and immediately add the stop bath. Agitate continuously for 30 seconds to one minute.
- Fixer: Pour out the stop bath and add the fixer. Agitate continuously for the first 30 seconds, then agitate for 5-10 seconds every 30 seconds for the recommended fixing time.
- Wash: Wash the film thoroughly. Follow the instructions for your fixer. A common method is the Ilford Wash Method: Fill the tank, invert it five times, and drain. Repeat with ten inversions, then twenty inversions.
- Wetting Agent: Soak the film in a wetting agent solution for the recommended time (usually one minute).
- Drying: Carefully hang the film to dry in a dust-free environment.
Step 6: Evaluating Your Results
After the film dries, examine the negatives carefully. Assess the contrast, grain, and shadow detail. Compare your results to your expectations. Keep detailed notes on your development process, including exposure settings, development times, and any observations about the final negatives. This information will be invaluable for refining your technique in future push processing sessions.
Frequently Asked Questions (FAQs)
1. Can I push color film at home?
While possible, pushing color film at home is more complex than pushing black and white. Color shifts are more pronounced and harder to correct. It’s generally recommended to have color film pushed by a professional lab for consistent results.
2. Does pushing film affect the grain size?
Yes, pushing film will increase the visible grain. This is a natural consequence of overdevelopment. The more you push, the more pronounced the grain will become.
3. What’s the best developer for push processing?
Many developers work well, but some are better suited than others. Ilford ID-11/Kodak D-76, Kodak HC-110, and Rodinal are popular choices. Experiment to find the developer that best suits your aesthetic preferences.
4. How much should I increase development time for a three-stop push?
A starting point for a three-stop push is to double or even triple the normal development time. However, significant adjustments will be required depending on the film, developer, and desired contrast. Extensive testing is necessary.
5. Can I push process expired film?
Yes, but the results will be unpredictable. Expired film tends to have lower contrast and increased grain, even when normally developed. Pushing expired film will exacerbate these effects. Consider adding a pre-fogging step before development and testing a roll first.
6. What is “N+1,” “N+2,” etc., referring to?
These terms refer to the amount of overdevelopment compared to normal (“N”). “N+1” means one stop of overdevelopment (pushing one stop), “N+2” means two stops, and so on.
7. How do I know if my film is underexposed?
Underexposed negatives will appear thin and lacking in density. Shadow areas will be virtually transparent.
8. Can I pull process film at home?
Yes, pulling film involves underdeveloping it to reduce contrast and highlight detail. The process is the opposite of pushing. Development times are reduced, typically by 10-30% for one stop of pull processing.
9. Is it better to push process or use a faster film?
Choosing between pushing film and using faster film depends on your goals. Faster films generally produce less grain than pushed film at the same effective ISO. However, sometimes the only film you have on hand is the one already loaded, or pushing offers a particular aesthetic that using a faster film would not achieve.
10. What’s the importance of accurate temperature control during development?
Consistent temperature is crucial for consistent development. Deviations from the recommended temperature can significantly affect the final results, leading to uneven development, increased grain, or unwanted contrast variations. Use a reliable thermometer and maintain the temperature throughout the development process.
11. How can I minimize grain when pushing film?
While you can’t eliminate grain completely, you can minimize it. Using a fine-grain developer, such as Ilford ID-11 diluted 1+1 or 1+3, and avoiding excessive agitation can help. Also, avoid pushing too many stops.
12. What happens if I over-agitate during development?
Over-agitation increases contrast and grain. It can also lead to uneven development if not done consistently. Follow the developer’s recommendations for agitation carefully. Use gentle agitation to ensure even development without excessive grain or contrast.