How to Push 400 ISO Film to 1600
How to Push 400 ISO Film to 1600
You've got a roll of 400 ISO film in your camera.
The light is getting shit.
You could go home.
Or you could just tell the camera it's 1600.
Well, sort of.
Pushing 400 ISO film to 1600 is one of our favourite ways to get a little more life out of a roll of black & white film, especially when you're shooting at night, indoors or just want to keep your shutter speed up.
And the best part?
You don't need to buy a roll of 1600 ISO film.
What does “pushing” actually mean?
When you shoot 400 ISO film at 1600, you're deliberately giving the film two stops less light than it was designed for.
Then, when the film is developed, you compensate for that underexposure by developing it for longer.
That's the push.
So:
400 ISO film → shoot at 1600 → develop +2 stops
It's not actually making your 400 ISO film magically become 1600 ISO film. You're changing the way you expose and develop it.
The result is usually more contrast, stronger grain and a slightly rougher look.
Which, depending on what you're shooting, can be exactly what you want.
Why would you do it?
The obvious reason is light.
If you're shooting street photography at night or indoors, shooting your 400 film at box speed might leave you stuck with slow shutter speeds or wide-open apertures.
Push it two stops and suddenly you can shoot at 1/500 instead of 1/125, or stop your lens down a little and keep your shutter speed fast enough to freeze what's happening.
It's particularly nice for manual-focus street photography, where having a faster shutter speed and a smaller aperture gives you more room to zone focus and react quickly.
And then there's the look.
Pushing film tends to give you more contrast and more visible grain. It's not necessarily “better” — it's just different.
And sometimes a bit of extra grit is exactly what the photograph needs.
What film works best?
Our go-to choices are Ilford HP5 Plus and Kodak Tri-X 400.
Both handle a +2 push really well, but you can experiment with plenty of other 400 ISO black & white films too.
Just remember that different films will react differently, so don't expect exactly the same results from every emulsion.
That's half the fun.
How do I shoot 400 at 1600?
There are a few ways to do it.
1. Change the ISO in your camera
If your camera lets you manually set the ISO, just set it to 1600.
That's it.
The camera will now underexpose the 400 ISO film by two stops.
2. Use exposure compensation
If your camera doesn't let you change the ISO but has an exposure compensation dial, set it to -2.
Just make sure the setting doesn't reset when you switch the camera off.
Some cameras are annoyingly good at forgetting things.
3. Hack the DX code
This is the fun one.
A lot of automatic point & shoot cameras read the DX code on the film canister to figure out what ISO film you've loaded.
If your camera doesn't let you manually change the ISO, you can modify that code so the camera thinks your 400 ISO film is 1600.
It's basically a tiny bit of analogue camera nonsense.
And we love it.
How to DX-code hack 400 → 1600
The DX code is the little grid of black and silver squares on the film canister.
Your camera reads those squares using electrical contacts inside the film chamber.
By removing one of the squares, you can change what ISO the camera thinks you've loaded.
For 400 → 1600, you need to remove the appropriate section of the DX code shown in the chart below.
You can use something with a hard edge to scrape it away — a coin works, or something similar.
Just don't go absolutely mental with it. You only need to remove a tiny section.
Once you've done it, put the film in your camera.
If everything went right, the camera reads the modified DX code and thinks:
“1600 ISO? Cool.”
Meanwhile, you know what's actually happening.
400 ISO film.
Shot at 1600.
Magic-ish.
Don't forget the important part
This is the bit that gets people.
You have to tell the lab.
If you shoot your 400 ISO film at 1600, tell whoever develops it that the film needs to be pushed +2 stops.
If you develop your own film, adjust your development time accordingly.
If you just hand the roll to a lab and say nothing, they'll probably develop it normally — meaning you'll have underexposed negatives that haven't received the extra development they need.
At Safelight, just write “PUSH +2” on your order or tell us when you drop the film off.
Go experiment
Once you understand the basic idea, you can start playing around with other combinations.
400 → 800 is a +1 push.
400 → 1600 is +2.
You can push different films different amounts, and you can also pull film when you want to go in the other direction.
Black & white film is generally the easiest place to experiment, but pushing colour film is possible too — the results just depend much more heavily on the particular film and process.
So next time the light starts disappearing, don't automatically pack the camera away.
Put some 400 in it.
Tell the camera it's 1600.
And see what happens.
That's the nice thing about shooting film. You can always make things a little more complicated than they need to be.
