Solargraphy

Solargraphy Pinhole Camera Fine Art Photographs by Bret Culp

Watch The Weather Network's short video ‘What is Solargraphy,’ part of the ‘Out of This World’ series, a collaboration I did with meteorologist and science writer Scott Sutherland.

  • The Weather Network’s “Out Of This World – Solargraphy: Capturing the Sun’s Journey in an Image.”

    Music [0:00]

    Scott [0:08]
    From summer solstice to winter solstice in 2023, three cameras on the roof of the Weather Network each captured a six-month record of the Sun’s motion across the sky. I spoke to photographer Bret Culp about this process known as solargraphy.

    Bret [0:21]
    Solargraphy is an alternative photography process. A normal photograph is typically exposed for a fraction of a second. Solargraphy is about capturing the movement of the Sun through the sky over days, weeks, months and longer, sometimes. This is a simple tube, as you can see, with a pinhole in it. So it’s really pinhole photography. When the light goes in, or the image comes in through the pinhole, it actually, what’s behind there is a piece of chemical light sensitive black and white photo paper. And the way the pinhole works is that the image is flipped, so the bottom [of the camera] is actually the top of what it sees out here.

    Scott [1:05]
    Right. We’re basically creating a record, then, I guess, of over, well, for this, for six months, because we came here six months ago, on the summer solstice and set these up. So we’ve created, we’ve actually captured, captured six months worth of the Sun passing through the sky, recording clear days.

    Bret [1:27]
    What it does capture, as you were saying, from the summer solstice, is the position where the Sun is highest in the sky, of course, and today, on the winter solstice, it’ll be the lowest. So, it captures that whole range. And the reason that it [the Sun position] changes is because the Earth has a tilt and it’s orbiting around the Sun. So there’s all of that science as well. I like to say that these things [solargraphs] are part art, part science and part chaos.

    Scott [1:52]
    You can’t just open this up and pull out a picture. So, how would you get the actual image out of this?

    Bret [1:58]
    Because it’s such an extreme over-exposure, you don’t develop it, otherwise it would go completely black. But you actually take it out, and it’s still light sensitive; you put it on a flatbed scanner–a computer scanner. You scan it. As you’re scanning it, you’re destroying it. So you get one shot. The resulting scan is a negative, and it’s mirrored, so you invert it, and then you flip it, and then you do a little bit of colour correction, or whatever, and typically you see these very colourful, unique images. The Chaos part of this is that sitting out there for a very extended period of time with extreme over-exposure, you end up with these very colourful images from black and white light-sensitive chemical photo paper. It’s got to do with the different kinds of photo paper, and they still make that stuff, not as much as they used to, but they still make it. The different chemical makeup of those different papers results in different casts or different colour tones as well. And then, you know, based on the temperature fluctuations during that period of time, whether it freezes, how humid it is during that time. If mould or bugs even, can get into the camera, water, whatever. It’s all part of it; it all adds to the surprise. And it’s all part of the fun. I love the surprise of this. It kind of gone in photography, right? That idea of we don’t know we’re going to get till we take it home and develop. Well, that’s what you get with this. And as you were saying, in that six-month period of time, you also get a chance to see six months of weather because where there isn’t a track, it was a cloudy day, similar to what it is today. And clearly where there’s a track, a sun track, it was a sunny day. And then you have the mixed day. So you have a record of six months of weather in this thing, making these things completely one-of-a-kind unique as well. 50% art, 50% science, 50% chaos.

    Scott [4:06]
    [Laughter]
    Very cool. Thanks, Bret.

    Bret [4:09]
    Thank you.

Part Art – Part Science – Part Chaos

Solargraphy is an alternative photography process that uses homemade pinhole cameras and light-sensitive black and white photo paper. It captures very long exposures of the sun's movement across the sky, transforming the passage of time into abstract visual records. Over days, weeks, and months, a single image is constructed, revealing a view of space, time, and weather patterns that we cannot normally see. The trails show the gradual day-to-day change of the sun's path due to the Earth's slightly elliptical orbit and 23.4° axial tilt. The missing or broken trails result from periods when clouds have obscured the sun.

The colours are not a straight depiction of the scene but a consequence of the paper's chemical reactions to extreme overexposure, the influence of uncontrollable factors such as moisture, dirt, or fungus that may have invaded the camera, and extreme temperature fluctuations. Additionally, each brand of photography paper has a different chemical makeup, which results in a different colour scheme.

Due to the long exposure, the paper should not be developed, as it would turn completely black. Using fixer will remove much of the colour. Instead, a high-quality flatbed scan is made of the “negative,” even though the paper is still light sensitive. This means that the light from the scanner will destroy the image as it works its way across the paper. The scan is then inverted, flipped, and colour and tonally processed in Photoshop.

Discover the fascinating interplay of art and science in Scott Sutherland's article, ‘Solargraphy: The Art, Science, and Chaos of Capturing the Sun’s Path in the Sky’, featured on The Weather Network. The article accompanies the video at the top of the page.

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