Last May, I spent a very pleasant few days in Paris, where I ran across this bookstore, Artazart. I bought a pleasing book with the allusive title of Thirty-six Views of the Canal Saint Martin, an old industrial canal near which the store is located, and had fun exploring the neighborhood, which is now becoming more or less hipster-ized. I also got a look at one of the few buildings built, and still standing, by Claude Nicholas Ledoux, i.e. the customs gate house.
I took note of their website, and went back for another look a few weeks ago and bought their pin hole camera kit by Stenoflex. Low-tech always interest me, and those images from the dawn of photography are fascinating. I thought it would be interesting to adopt their technique in this obsessively digital age, so I bought the STÉNOFLEX CLASSIQUE NOIR.
It’s a simple cardboard camera obscura, or pinhole camera, complete with ten 3.5″ square sheets of photo developing paper, a red filter sheet for a light in your darkroom, packets of developer and fixer crystals, with instructions. Since it’s made of cardboard, actually heavy construction paper, and the shutter is activated by a slide mechanism (the pointing hand pull-tab), it didn’t hold up too well.
After a few uses, the shutter slide began to crease, and it became hard to move. Looking at the pinhole under a magnifier showed that it had become very distorted, still, I did manage to get some nice images by fixing it to my tripod with rubber bands.
The picture above shows the camera after I addressed the deterioration of the paper structure by purchasing a laser-drilled pinhole (0.2mm) on ebay for about $8.00. Instead of a cute paper pull-tab, I have a piece of black photographer’s tape for a “shutter,” which works fine since the exposure times are anywhere from fifteen seconds to over an hour. Here are two shots showing the inside of the Stenoflex, with the new aperture taped in place, and outside view of the aperture and shutter.
I was able to calculate the approximate specifications for the original Stenoflex because I happen to have an old micrometer that I took from my father’s garage when we cleaned up his stuff after he died three years ago. I took a needle from a sewing kit, examined the pinhole under magnification with a jeweler’s loupe while I inserted the needle into the hole. I was able to see that it was a close fit, and I subsequently determined the needle diameter with the micrometer.
The needle was 0.024 inches in diameter (0.61mm). The original camera configuration has a focal length that I measured to be about 1.8 inches (46mm), giving an f-number of about 75. By flipping the tabs on the backplate that holds the photo paper in place (the square with the four semi-circles for the corners of the paper), it’s possible to decrease the focal length by half, to about 0.9 inches, giving an f-number of about 38.
My understanding of all these things – I am NOT an experienced photographer – was aided superbly by the little ebook, From Pinhole to Print, that I found at the website of AlternativePhotography.com, and which is well worth the eight dollars or so that I paid for it. It contains tables that are useful for designing your own pinhole camera, explanations of the basic math behind f-numbers, and recommendations for exposure times.
Pinhole photography has become quite popular among the alternative-tech minded, but I have found that most of these people shoot onto film, which they then develop and print either in a darkroom, or by digitally reversing and enlarging the negative image. I don’t know what the people shooting with color film do, but I prefer to stay at the most basic level. I shoot my images onto photographic paper; develop them in my primitive darkroom; then scan them and reverse the imagery on my computer, From there, I can manipulate them with IrfanView or GIMP, both free software applications.
By dint of some research and fiddling with various tables for exposure times I was to able to estimate the ISO of photo paper at about a value of 5, that is, REALLY SLOW… I might be off a bit, but all the numbers seemed to jive, and this made it possible for me to use a light meter, purchased for my iPad for $0.99, to get better estimates for exposure times. The system seems to be working well, but it’s not perfect – we are not doing 21st century photography!
The image below, and the one at the top of this post, were taken with the original Stenoflex setup: naturally a double-exposure of myself was my first attempt. It was a sunny day, and it worked fairly well for a first try with a primitive camera.
This image was taken from the attic window of my house, and I call it Hommage à Nicéphore Niépce
After I got my hi-tech pinholes, I took some shots with the modified Stenoflex, and with the 0.2mm aperture, I took two shots with focal lengths of 0.9″ and 1.8″. The day was too far gone to give strong light, but the image is definitely more sharp.
It occurred to me that I could increase the focal length of the camer even more by not fully collapsing the lid onto the base, sort of a bellows effect, so I got the next shot with a focal length of about 3-inches. Much tighter image, and some solarizing on the right. Arguing with myself again…
This outdoor shot used the 0.2mm aperture, with a focal length of about 2.5-inches. It was a cloudy day, so I exposed it for fifteen minutes, a bit too long I’d say.