A 370-Day Exposure

SOLARGRAPHY:  n.  A technique in which a fixed pinhole camera is used to expose photographic paper for an absurdly long amount of time … mostly used to show the path taken by the sun across the sky. (Wikipedia)

I know this solargraphy stuff doesn’t appeal to everyone. It’s probably of interest mostly to earth-science geeks, die-hard pinhole photographers, and others who tinker late into the night in their garage workshops. I’m a bit of each, though not to extremes, yet once I tried making solargraphs with home-made pinhole cameras, I was hooked. Strange? Definitely, but harmless. And there are hundreds of us practicing this arcane craft all over the world every day.

On October 2, 2011, I attached a paint can with a small pinhole and a sheet of photographic paper to a cottonwood tree in Mono County, pointing toward the morning sun behind some more trees and some old buildings. On October 6, 2012, I retrieved the camera and brought it home. I scanned the unprocessed paper, inverted the negative image, increased the contrast, and adjusted the colors. Exposure: 370 days (February had an extra day this year) at f/200-and-something.

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Tim Messick Photography • Graphics
Copyright © 2012 Tim Messick. All rights reserved.

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About Tim Messick

Photographer, cartographer, and botanist/naturalist. Home is in Davis, California. Home-away-from-home is the eastern Sierra Nevada. Compiling a flora of the Bodie Hills.
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3 Responses to A 370-Day Exposure

  1. Greg says:

    Hi Tim, I guess I fall in the “earth science geek” category. I’m trying to figure out why there’s such a clean and complete division between bright solar paths on the left and dim solar paths on the right. Since the camera was pointed east from the northern hemisphere, let’s see… the sun should rise in the middle at the autumnal equinox (about when you put the camera up), drift right until winter solstice, drift all the way left until summer solstice, then drift back towards the middle when the next autumnal equinox is reached (about when you removed it). So the solar paths reflect two complete passes. Is it possible that this location was uniformly cloudy for roughly 6 months (autumnal equinox to vernal equinox), with not a single day of sunshine?

  2. Tim Messick says:

    Hi, Greg. You do come up with the best questions! I’ve noticed what you are asking about and it puzzles me also. I have a possible explanation, but first, a couple of observations.

    (1) I realized after posting this that I forgot to flip the image left-to-right. So we’re looking east, but north is on the right and south is on the left (should be the other way around). So the rising sun paths begin in October (right side of the bright zone), move to the south (left) until late December, then move north again (right) until late June, then return to about where they began. But the earlier sun paths are much brighter than the later ones. (2) In looking at other solargraphers’ images, I’ve noticed similar effects, but often less pronounced than in mine.

    Here’s my theory: It’s the paper. The paper seems to become less sensitive, even to a bright, small, pinhole image of the sun, as the exposure progresses. I don’t know why, but it may be exposure to heat, or pre-exposure to the much less intense light in the rest of the scene, or something else. People use lots of different photographic papers for solargraphs, and I think it’s time for me to try a different brand. Clearly, this is not quite the use these papers were designed for, so different emulsions can be expected to respond differently.

  3. drawandshoot says:

    That is an interesting photograph, Tim.
    i like the idea of something being exposed for an entire year. Cool!

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