Pushing film means shooting it at a higher ISO than its box speed, which underexposes it, and then developing it for longer to make up the difference. Pulling film is the opposite: shooting it at a lower ISO than box speed, which overexposes it, and developing it for less time. Pushing lets you shoot in less light at the cost of more contrast and grain; pulling lowers contrast and tames harsh light. Neither changes how sensitive the film really is, and the whole roll has to be treated the same way.
Each stop of push or pull doubles or halves the rating. Shooting a 400 film at 800 is a one-stop push; shooting it at 1600 is two stops. The rating you shoot at is called the exposure index, or EI, to keep it separate from the box speed.
Push and Pull at a Glance
For a film with a box speed of ISO 400:
| Shoot at | Change | Exposure | Development | Result |
|---|---|---|---|---|
| EI 100 | Pull 2 stops | 2 stops over | Much shorter | Very low contrast, soft and smooth |
| EI 200 | Pull 1 stop | 1 stop over | Shorter | Lower contrast, gentle highlights |
| EI 400 | Box speed | Normal | Normal | The film as designed |
| EI 800 | Push 1 stop | 1 stop under | Longer | A little more contrast and grain |
| EI 1600 | Push 2 stops | 2 stops under | Much longer | Clearly more contrast and grain, thinner shadows |
| EI 3200 | Push 3 stops | 3 stops under | Longer still | Heavy grain, hard contrast, little shadow detail |
The same pattern applies to any film: double the box speed for each stop of push, halve it for each stop of pull. The exact development times come from the film and developer maker’s data sheet, or from your own tests.
What Pushing Does to a Negative
Underexposure leaves the shadows with too little exposure to record detail. Longer development cannot create detail that was never recorded, but it does build up density in the midtones and highlights, which carry plenty of exposure. The result is a printable negative with more contrast than normal: shadows go dark and empty, midtones and highlights look normal or bright, and grain grows more visible with each stop.
That trade is often worth it. Pushing lets you keep a fast enough shutter speed to stop motion or hand-hold the camera in dim light, at concerts, indoors or at night, without flash. The look of pushed black and white film, gritty, contrasty and grainy, became part of the visual language of photojournalism and street photography, and many photographers push for that look even when they have enough light.
What Pulling Does to a Negative
Overexposure gives the shadows more than enough exposure, so they keep full detail. Shorter development then holds back the highlights so they do not become too dense. The result is a negative with lower contrast and a longer, gentler tonal range, with grain that is usually less prominent.
Pull when the light is harsher than the film can handle, such as strong sun with deep shade, a backlit subject or a bright beach, or when you need a slower film to use a wide aperture or slow shutter in bright light. Pulling also rescues a roll shot at the wrong speed by mistake: if a 400 film was shot at 100, ask for a two-stop pull.
How to Push or Pull a Roll
- Decide before you start the roll. Every frame on the roll gets the same development, so every frame should be shot at the same rating.
- Set the camera’s ISO to the new rating and meter normally. With a handheld light meter, set the meter to the new rating instead.
- Mark the roll. Write the rating or the push on the film cassette or on a piece of tape on the camera, such as “EI 1600, push 2,” so it is not lost when you rewind.
- Develop for the new rating. Tell the lab how many stops to push or pull; most labs offer it as a standard option. If you develop film at home, use the push or pull time from the data sheet for your film and developer, and keep notes so you can adjust next time.
Some developers are better suited to pushing than others, and two-bath developers are often used because they hold back highlights while the shadows keep developing. Your choice of developer affects grain and shadow detail as much as the time does.
Black and White, Color Negative and Slide Film
Black and white film is the most forgiving. One or two stops of push is routine, three stops works when you want a rough, high-contrast look, and pulling one or two stops is a reliable way to handle hard light.
Color negative film can be pushed one or two stops, but expect stronger contrast, more grain and some color shifts that need correcting in printing or scanning. Color negative film has a lot of room for overexposure, so many photographers handle bright light by simply rating it a stop slower and developing normally rather than pulling.
Color slide film has very little exposure latitude, so it behaves differently. Pushing raises contrast, can shift colors and weakens the deepest blacks; pulling softens contrast. Because slides are viewed directly, there is no printing stage to correct the result, so test before relying on it.
Pushing Film and Raising ISO on a Digital Camera
The idea carries straight over to digital. Raising ISO does not make the sensor collect more light; it brightens a signal that was recorded with less exposure, much as longer development brightens an underexposed negative. In both cases the price is noise or grain and lost shadow detail. The difference is that a digital camera can change ISO frame by frame, while film commits the whole roll.
Push and pull are also how the zone system controls contrast. Its N+1 and N−1 development are the same longer and shorter times, used to expand or compress the tones of a scene rather than to change the film’s speed.
Developing your own pushed rolls? How to Develop Film at Home walks through the equipment, chemicals and steps for black and white and color film, including push and pull development.
Common Mistakes
- Pushing only some frames on a roll. Development affects the whole roll, so mixed ratings mean some frames will be wrong.
- Forgetting to mark the roll. Once rewound, a pushed roll looks like any other. Label it at once.
- Expecting shadow detail from a big push. Pushing brightens the midtones; it cannot recover shadows that received too little exposure. Compose so the important parts of the picture are lit.
- Pushing slide film for an important job without a test. Its narrow latitude makes results less predictable than with negative film.
- Confusing a pull with simply overexposing. Rating color negative film slower and developing normally is overexposure, which is often fine. A pull also shortens development.
Try This: Compare a Push Side by Side
Load two rolls of the same black and white film. Shoot one at box speed and the other pushed two stops, photographing the same few scenes on each: one in shade, one in mixed light, one at night. Have the second roll developed for the push. Lay the negatives or scans side by side and look at three things: how much detail survives in the shadows, how bright the highlights are, and how large the grain looks. One comparison teaches you more about when a push is worth it than any table.
Curious how grain changes with film speed and development? Film Grain explains what grain is and why faster film and longer development show more of it.
Pushing and Pulling Questions
What does it mean to push film? It means rating film at a higher ISO than its box speed, which underexposes it, then developing it longer to compensate. A 400 film shot at 1600 and developed for 1600 is pushed two stops.
What does it mean to pull film? It means rating film at a lower ISO than its box speed, which overexposes it, then developing it for less time. The negatives have lower contrast, which helps in harsh light.
How many stops can you push film? One or two stops gives good results with most black and white and color negative films. Three stops is possible, especially with black and white, but shadow detail is mostly gone and grain is heavy.
Does pushing film increase grain? Yes. The longer development that brings up an underexposed negative also makes the grain more visible, and the effect grows with each stop of push.
Can I push just one frame? No. The whole roll is developed together, so every frame gets the same push or pull. Sheet film is the exception, because each sheet can be developed on its own.
New to shooting film? Film Photography covers film formats, choosing a film, metering for film and getting rolls developed and scanned.