A while back I took an interest in infrared photography, and I bought a couple of rolls of Maco 820c infrared film. Using infrared film involves a huge amount of trial and error, and unlike digital cameras, you can’t take one or two pictures and check after each one. You have to shoot a whole film.
My camera’s light meter seemed to be responsive to infrared light, so I let it handle the exposures. Unfortunately I now know that the readings were nonsense, because the film came out almost entirely blank. The pictures that I salvaged weren’t good enough for my photo blog but I did write about the experiment.
This time, with my last roll of Maco film, I decided against trying to do any formal kind of metering. I left the aperture either at f/5.6 or f/8, as it seemed sort of sensible. You don’t want the aperture too small, because the longer wavelength of infrared light will cause diffraction at the diaphragm more easily. Equally, you don’t want it too big because this makes the depth of field smaller. Focussing infrared is already difficult as you can’t see it with your eyes, and has to be done using a red dot on the focus ring. By having a larger depth of field, you can get away with a larger inaccuracy before it looks blurred.
I put the camera in bulb shutter mode and guessed at the exposure time, judging by how brightly the sun was shining, and how warm it felt on my face. I generally exposed for between 5 and 30 seconds.
This time – great success. Practically every image was exposed well. A handful were a bit under- or over-exposed and had lost detail in shadows or highlights, but what can you expect when you choose the exposure time by looking at the sky?
I took a few pictures of a fire in a chimenea. These came out completely blank, so I guess the fire wasn’t emitting anywhere near as much infrared radiation as I thought. I suppose while it feels very hot, it isn’t that bright to look at. The film is sensitive up to 820nm and the filter allows wavelengths longer than 720nm. This is a reasonably wide range, but it’s still “near infrared” (almost-red light) rather than “far infrared” (heat).
The end result is that I’ve created images that are ghostly and every bit as “odd” as I had hoped, from looking at other people’s work. You can see the best pictures from the film on my photo blog.