Years ago in Wired magazine they showed a photograph that was a six month exposure. I remember being captivated by the thought of taking a picture for such a long period of time. Unfortunately, Wired didn’t give any info about how the photo was made. Fast forward to a few months ago when I came across another six month exposure. Fortunately this photo came with a little more explanation. It was called a solargraph.
There is amazingly little information online about solargraphy or how to make a solargraph. Trial and error being the best teacher I decided to do some experiments and teach myself how to create these images. The following is my attempt to document my experiments and hopefully give you some details that will help if you want to tackle the world of the solargraph.
So what is a solargraph? A solargraph is a photograph that was made by making an exposure long enough to track the movement of the son in the sky. Exposure time can be anywhere from a couple hours to six months.
How do you make a solargraph? A solargraph is typically made using black and white photo paper instead of traditional film. The reason for using photo paper is that it is less sensitive than film. Photo paper is 20-200 times less sensitive than film. This allows the paper to survive unthinkably long exposure times without getting over exposed.
What kind of a camera do you use? Solargraphs are typically made with a pinhole camera because the extremely small aperture (the hole that lets light in). However, I have had success making solargraphs using lens cameras. Simply load the camera with photo paper where the film usually goes. Then rig your camera so that the aperture can stay open indefinitely. Since a typical camera lets more light in than a pinhole camera your exposure time will be significantly shorter. By using a lens you can make a half-day to week long exposure. A pinhole camera is ideal for longer exposures of a week to several months.
How do you process the photo paper? Unlike a print made in a darkroom, the photo paper you use to make a solargraph is never ran through photo chemicals. This may come as a surprise to anyone with darkroom experience. Because the exposure time is so long the image actually appears on the paper without processing! If you were to run the paper through developer it would turn instantly black.
How do you preserve the image if you can’t use chemicals? After the photo has been taken you need to immediately scan the paper. Scanning itself will damage the paper because it is till light sensitive. You get one good scan before the paper starts getting dark and destroying your image. I have not come up with a reliable way to preserve the photo paper. Fixer seems to destroy the image, although not completely. If someone has a solution to this dilemma please share it.
Does a solargraph result in a black and white or color image? This is perhaps the most amazing thing about solargraphy. The image is made using black and white photo paper. The image that is created is in color! I can’t really explain how this happens, but it does. I suppose that since the paper is never ran through the the typical chemicals it is able to preserve some color.
I will try to update this page as I learn more about how to make solargraphs. If you know of resources or can correct any of my mistakes please let me know.