Solargraphy is a photographic method of capturing the paths of the sun over extremely long exposure times. Using light-sensitive black and white photo paper and homemade pinhole cameras I was able to take these photos over almost two weeks.
The light from the pinhole causes the paper to darken and in my case, turn blue and purple. Other brands of black and white paper will result in different colours. Once you finish exposing the paper you're left with a negative which can be scanned and inverted digitally which is why mine have a sepia brown and green colour.
The last three photos in the series are results of experimentation with pinhole cameras with more than one pinhole. Solargraphs #8 and #9 from the series only had an exposure of 1 and a half days, which is why you can see one distinct curve and a fraction of another one. The synchronised repetition of the sun path in these photos comes from the several holes in the camera which despite only having an exposure of just over a day, were much darker than the rest because the extra holes let in so much more light in comparison.
It was an extremely interesting project and I'm keen do more over even longer periods of time to capture more of the sun's path.