Pushing film - an experiment

As I continue to learn all about film, I'm always looking to try a new technique or method.  Twitter is a great source of information, particularly using #believinfilm or #filmisnotdead - on the former I have seen some great work with pushed film, and so I decided to try it for myself.

What is "pushing" film?

I know I might be pointing out the obvious to many people, but I thought it'd be useful to some of you out there to briefly explain what it actually is - when I researched this, I discovered I had actually been doing basically the same thing with some of my digital files!

The key ideas behind pushing film are to:  

  1. Rate the film at a faster speed - in other words, if you have an ASA 400 box speed film (e.g. Ilford HP5+), set your meter at 800 or even 1600 ISO.  This means essentially you are under-exposing your film by one or two stops respectively.
  2. If you have the film developed by someone else, it is really important that you tell them the ISO you shot it at, because....
  3. When you develop the whole roll (you can't just push some frames on a roll, because you develop the whole roll the same), you need to adjust development times accordingly.  This is because the lack of exposure from the last step is compensated for by the chemicals.  For example, all the images in this post were pushed to ISO 1600 (from a box speed of 400).  When developing, I increased the develop step from 9 minutes to 13 minutes (at 20 degrees) using DD-X.

Why bother?

Well, by increasing the speed of the film, you can gain up to two stops of shutter speed.  So if you were shooting something in lower light and say you had a meter reading of 1/15th of a second, you could push the film to 1600 and get a shutter speed of 1/60th of a second.  This is much more manageable hand-held.  

Some people push film not necessarily for the faster shutter, but for the increased grain and contrast.  It does increase it quite a lot, which is why people recommend you don't push more than two stops.  The grain can be quite heavy, but I didn't think it was too oppressive - you can see for yourself below.

What do I think?

I actually quite liked the effect I got from the film.  I was shooting late afternoon in the winter, and so there wasn't much available light.  I tried it on just one roll of 120 Ilford HP5+, and most of the images were being taken at 1/60th of a second, at ISO 1600.  I did see higher grain, but then again, that might only be noticeable if I pressed my face right up to the image....There was still a lot of detail in the shadow areas, as you can (hopefully) see below.  

Let me know what you guys think, and why not give it a go yourself.  Share your results with me on Twitter!