{"id":3680,"date":"2023-09-13T16:55:46","date_gmt":"2023-09-13T23:55:46","guid":{"rendered":"https:\/\/thelawlers.com\/Blognosticator\/?p=3680"},"modified":"2023-09-13T19:40:43","modified_gmt":"2023-09-14T02:40:43","slug":"musings-on-pinhole-photography","status":"publish","type":"post","link":"https:\/\/thelawlers.com\/Blognosticator\/?p=3680","title":{"rendered":"Musings on pinhole photography"},"content":{"rendered":"\n
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If you\u2019ve been reading this blog, you know that last week I returned from the 2023 Burning Man festival in northern Nevada. It was a terrific event, full of excitement and artistic energy \u2013 until it rained. Then it became a less than wonderful mud bog. We managed; we survived; we will return next year and try again.<\/p>\n\n\n\n

My camp is called the Pinhole Project.<\/em> Our artistic endeavor is to document the art installations at Burning Man using large pinhole cameras on photographic paper. For this we have 10 55-gallon Kraft paper barrels, each with metal plates glued inside, and each with a precision-cut pinhole aperture in a sheet of aluminum that is cemented into the side of the barrel. On top of each pinhole is a \u201cshutter\u201d made out of gaffer\u2019s tape.<\/p>\n\n\n\n

We insert a large sheet of photo paper into each barrel in our darkroom \u2013 built inside a 20-foot container cargo box \u2013 and hold that paper in position with magnets. We then put a steel lid on each barrel, making the entire thing light-tight. Once loaded with photo paper, the cameras are ready for the field.<\/p>\n\n\n\n

Every morning we hold a public workshop in our gallery. Interested people show up, sometimes in surprising numbers. We explain how the cameras work, how we develop the photos, and how we re-photograph each finished photo for our digital archive. At the end of the workshop, we invite those present to join us on the Playa to make new photographic images. We have a big pick-up truck for transporting the cameras.<\/p>\n\n\n\n

The photographic paper we use is made by Foma in the Czech Republic. It\u2019s designed for use under an enlarger in a darkroom, so the ISO is not published. But we have a Weston Master V light meter and we have used it to estimate the paper\u2019s ISO at about 0.3. This requires a long exposure in the bright sunlight of the Black Rock desert. Our typical exposure time is about 45 seconds.<\/p>\n\n\n\n

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This is my No Dancing pinhole photo. These photos are negative and reversed. Once they are dry we re-photograph them for our digital archive. There, we invert the image and flip it so that it appears normal.<\/figcaption><\/figure>\n\n\n\n

If people will be the subject of a pinhole photo, those people must stand still for 45 seconds \u2013which is very difficult. We do our best, and the results are very impressive.<\/p>\n\n\n\n

One day I took the group out onto the Playa to make photos. I had an idea I wanted to explore. There was a huge sign erected on the Playa saying \u201cNO DANCING\u201d \u2013 and I decided to take a large pinhole photo of a bunch of people dancing in front of that sign. It was a simple photo to organize, moving people into place, moving the camera to the right spot. We use wooden camera supports that look like medieval torture devices; each is a plywood piece with teeth on each side. There are two level edges for each tooth so that the large barrels can be placed in a number of positions on the support. We often add a bungee cord to stabilize the camera in wind.<\/p>\n\n\n\n

The No Dancing photo turned out very nicely, and I am very proud of it.<\/p>\n\n\n\n

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This is the inverted, reversed and tonally adjusted version of the No Dancing photo.<\/figcaption><\/figure>\n\n\n\n

A couple of days later I went back out on the Playa with a friend and we took three more large pinhole photos. Mine was a horizontal portrait of three inflated spheres of the Earth, the Moon and Mars that were on the edge of the Playa. These works were exceptional. They were printed on Mercator sections of fabric, then sewn into complete spheres. Illuminated at night, they were a spectacular sight.<\/p>\n\n\n\n

I set up the camera and took a one-minute exposure \u2013it was slightly overcast. Then we moved on to take a couple of other images.<\/p>\n\n\n\n

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My very capable camp mate Blanka Hodur is directing the dancers for the No Dancing pinhole photo.The camera is standing on one of our wooden camera stands.<\/figcaption><\/figure>\n\n\n\n

Back in the darkroom, we processed all that day\u2019s images, and mine looked very nice. But Mars had an egg shape, a significant distortion of its otherwise spherical shape. I knew this had not been caused by wind, so I assumed it was a camera distortion. Occasionally we have a sheet of photo paper fall inside the barrel when a magnet isn\u2019t placed correctly. This usually causes blockage of part of the image, but it doesn\u2019t cause distortion.<\/p>\n\n\n\n

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This is the digital version of the Earth, Moon and Mars photo. Note the egg-shaped distortion of the sphere on the left. This confused me. You can see similar, though not as extreme, distortion on the Earth sphere.<\/figcaption><\/figure>\n\n\n\n

I needed to understand why this distortion was there.<\/p>\n\n\n\n

I have drawn two pinhole cameras here: one is the camera we use at Burning Man. It\u2019s a Kraft paper 55-gallon drum with its pinhole aperture on one wall of the camera. The other is an idealized pinhole camera that has its aperture at an optical center that is equidistant from all points of the photo material.<\/p>\n\n\n\n

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This is the pinhole camera we currently use. The distance A is the center; the distance 30\u00b0 off of center travels just 84 percent as far, and the light at the edges of the photo travels only 47 percent as far. This, I think, explains the distortion I am getting in the spheres photo.<\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

The current camera is far from ideal in terms of its optical path. Light coming in on the edges travels slightly less than half the distance that light travels in the center of the image. I am pretty sure this explains the distortion. The light along the outer edges of the image is traveling much less than the light in the center, and thus, it is being distorted along one axis. The other axis is affected similarly, but to a lesser degree because it\u2019s a smaller difference between the center and the edges of the photo paper.<\/p>\n\n\n\n

\"\"<\/a>
This is my idealized pinhole camera. All light entering the camera through the aperture travels the same distance to the photo material, shown by the lines labeled A. This, I believe, would eliminate the distortion. I\u2019m not sure I want to eliminate the distortion, but I might build one to test it. Because the circumference of the curve is smaller, compared to our existing cameras, the photos would also have a different aspect ratio, and the width would be smaller.<\/figcaption><\/figure>\n\n\n\n

The idealized pinhole camera would be pretty easy to make and test. I might try it by inserting a modified film plane into a barrel to normalize the distance that the light travels after it enters the camera through the aperture. With that I am quite sure that optical distortion would be eliminated on the circumferential axis.<\/p>\n\n\n\n

I\u2019ll keep you posted!<\/p>\n","protected":false},"excerpt":{"rendered":"

If you\u2019ve been reading this blog, you know that last week I returned from the 2023 Burning Man festival in northern Nevada. It was a terrific event, full of excitement and artistic energy \u2013 until it rained. Then it became … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31,12,11,10,30],"tags":[63,64,416,989,988,973,985,108],"class_list":["post-3680","post","type-post","status-publish","format-standard","hentry","category-adventures","category-art","category-people","category-photography","category-technology","tag-blognosticator","tag-brian-lawler","tag-burning-man","tag-pinhole-camera","tag-pinhole-photo-optics","tag-pinhole-photography","tag-pinhole-project","tag-the-blognosticator"],"_links":{"self":[{"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=\/wp\/v2\/posts\/3680","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3680"}],"version-history":[{"count":4,"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=\/wp\/v2\/posts\/3680\/revisions"}],"predecessor-version":[{"id":3690,"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=\/wp\/v2\/posts\/3680\/revisions\/3690"}],"wp:attachment":[{"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3680"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3680"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thelawlers.com\/Blognosticator\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3680"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}