Pushing a 400 Film to 1600
The light in November leaves at four in the afternoon, and a 400-speed film in a camera whose lens opens to f/3.5 is not enough for anything indoors. So I shot a roll at an exposure index of 1600, two stops underexposed, and compensated in the developer. This is called pushing, and everything I had read said it would cost me shadow detail and add grain and contrast. All of that turned out to be true, and the pictures were still worth having.
The development was the standard fine-grain developer I use for everything, at stock strength rather than my usual 1+1 dilution, at 20 °C. The time I chose was 14 minutes 30 seconds against a normal time of 7 minutes 45 seconds, which is roughly the manufacturer’s suggestion for a two-stop push with a little added because my water is cold and I suspect my thermometer reads high. Agitation was gentler than usual: five inversions in the first thirty seconds, then three inversions every minute, on the theory that less agitation holds the highlights back while the shadows catch up.
The negatives came out dense in the highlights and thin in the shadows, exactly as predicted. On the light box the frames shot in the kitchen under a single bulb have a good range in the mid-tones and black, empty shadows. The frames shot by a window with the lamp on look nearly normal. The grain is visible at 18 by 24 cm but not ugly; it has a gritty, even texture that suits the dim rooms.
Printing them was a lesson in its own right. The contrast in the negatives is high enough that I printed at grade 1.5 rather than my usual 2.5, and I still had to burn in the window in two frames for an extra eight seconds to stop it going completely white. Two frames, where I had misjudged the light and underexposed by three stops rather than two, were unprintable: there is simply nothing in the shadows to bring up.
For the record, what I would do differently: meter for the shadows rather than the whole scene, since the push can save highlights but cannot invent shadow detail; and bracket the first few frames in a dim room until I trust the meter in that light. The roll gave me eleven prints I like out of thirty-six, which for a first attempt in a dark kitchen I will take.