[Editor’s Note – James here with a quick message to introduce the next contributor to our new Tips and Techniques segment. Cameron Kline is someone you may be familiar with; he’s an editorial photographer and the founder of Film Shooters Collective. Today he tells us all about push processing – what it is, how to do it, and why we should care. Enjoy.]
Have you ever found yourself in an ideal situation with a less than ideal film in your bag? It’s a sunny day, so maybe you grabbed something in an ISO 100, but later find yourself in an overcast or fading light situation. Or maybe you only have access to ISO 400 film and you need something even faster for a concert. Regardless of the details there is a solution when you have the need for speed; you can push your film.
Before we get any further I think it’s important to cover the basics and talk about what it actually means to push film, which is a two step process. We push film when we first under-expose the film in our camera and then later compensate for that under-exposure by over-developing the film. An ISO 400 film, for example, exposed at ISO 800 and developed to compensate for the under-exposure would be said to have been pushed one stop. Or an ISO 400 film exposed as if it were 1600 speed film and over-developed to compensate for the under-exposure would be said to have been pushed two stops.
When I shoot street photography, I shoot Ilford HP5+ pushed one stop almost without exception. The reason for this is simply that I want to have the highest possible shutter speed that I can to freeze any movement in the frame, and also so that I can have the smallest aperture possible to extend my depth of field. On sunny days this equates to me maxing out the shutter speed at 1/1000th of a second and a working aperture of F/8. This combination also allows for some flexibility when the light starts to fall in the early evening hours.
Now, this process is not for everyone or every shoot, and there are some things you need to be aware of before you load your camera up and head out. The first thing that you should note is that pushing your film will increase both the grain and the contrast of your negatives. And contrast and grain continue to increase for every additional stop you push the film, so it’s important to take that into consideration before shooting. This isn’t something you’ll want to use at a wedding or engagement session until you’ve had a chance to test it and see if the grain and contrast fit your style.
Second, once you’ve snapped that first photo you’re committed to finishing the roll at the speed or push you’ve chosen. If you decide to change speeds or forget you’re pushing, and shoot half the roll pushed and half the roll at box speed, you’ll be forced make a tough decision come development time. So while pushing film is one of the most handy techniques you can add to your photographic repertoire you need to be aware of the considerations it brings as well.
Your homework today is to push process a roll of film and enjoy the results. Don’t worry – it’s not hard.
To get started pushing your film, choose a developer and film combination that’s flexible. The best developers that come to mind for pushing are D-76, Rodinal, or HC-110. As for film choice, I would choose Kodak Tri-X or Ilford HP5+. The results from either of these films will be pretty similar, so the decision will likely come down to a cost consideration or brand allegiance. Once you’ve picked your poison, refer to the manufacturers’ data sheets or Massive Dev Chart to learn the required development times for push processing.
Good luck! And let us know how it goes in the comments.