About five months ago I was inspired to try "solargraphy" for the first time. I first heard of this kind of photography - making very long pinhole exposures that show the changing position of the sun in the sky over weeks, or months - through the work of Jesús Joglar, and I was further inspired by the river project Johanna Moore did up in Maine. I exchanged some emails with Jesús, who pointed me to some how-to articles from Diego López Calvín, a pioneer in this practice.
The cameras are utterly simple - really any light-tight container will do. I chose aluminum drink cans. I made half of my cameras with the pinhole centered on the can, and half with the pinhole offset by about 20mm, to experiment with a pinhole equivalent of rise and fall camera movements. Each can got a piece of RC photo paper inside, and was sealed up with electrical tape. I placed the first few test cameras in November 2014, and placed about 20 more just before the winter solstice - when the sun is lowest in the sky. It's an interesting problem to find a place to tape up a tin can (securely, for a period of many weeks), where the can will face south (and catch the sun) and frame a potentially interesting subject. I wondered how many of the cameras would still be there when I came back to collect them.
For me, the hardest part was waiting many weeks to see what the paper might hold. A lot of snow fell, and made it harder to get to some of the cameras, which helped me to leave them alone. By now, I've "harvested" most of them, and the images that were created show what worked and what didn't. It turns out that shifting the pinhole up can be a good idea, and shifting it down, so far, not so good. Using a round can mounted vertically does interesting things with perspective at the edges of the frame. Now... if I put up more cameras quick, maybe I can get in another round before the leaves come in...
More solargraph images can be found in the gallery linked at left.