[Student Projects, Photography]

Pinhole Photography

In Dr. John Bordley's Chemistry and Art class at the University of the South, each student was required to do an individual project. I had no idea what subject to do mine on until Dr. Bordley suggested that I make a pinhole camera and take pictures with it. Since I had never heard of a pinhole camera, much less made one, he had to explain to me that a pinhole camera is a homeade camera that produces negatives by letting light in through a tiny hole. Since the light is reflected off whatever the camera is aimed at, it produces an actual image on the film instead of just a blur of light. The camera can be made out of any container, as long as this container doesn't let light in until the hole is uncovered. I also found information on several webpages, especially The Pinhole Page (link no longer available), about pinhole cameras. I owe thanks to Dr. Bordley for providing advice, film, and chemicals; to Bud Sutherland in the Woods Labs basement for generously donating the hardware I needed, including an entire roll of black electrical tape; and to my classmate Amanda Wolfe for her collaboration and commiseration in the evil darkroom.

Original Plan

I began this project with the goal of experimenting with as many combinations of variables as possible to find the best way to take pictures with a pinhole camera. My plan was to make two different cameras, one out of a round container and one out of a rectangular box, to see if the shape of the camera affected the picture. In each camera, I planned to have two positions for a pinhole, with one position farther away from the film than the other, to test the effect of the distance from the pinhole to the film. I also planned to make several pinholes of different sizes in order to find out how varying the size of the pinhole changed the image produced. Additionally, Dr. Bordley had three types of film available, paper film (coated with a silver bromide emulsion), Kodak Ortho film, and Ilford Ortho film, so I intended to see which kind produced the best pictures. Finally, I knew that I would be changing the amount of time I exposed the film to light, and I also knew that, since I planned to take pictures in sunlight, the intensity of the light would change.

With all these variables in mind, I began to construct a camera using a cylindrical Kroger Oats box that Dr. Bordley had in his office. I spraypainted the inside of this container black to keep light from bouncing around inside the camera and cut two holes in it, one in the bottom (24 cm from lid) and one in the side (13 cm from other side). Then I drilled four "pinholes" in pieces of aluminum like the approximately life-size one shown below.

That hole, which doesn't show up clearly in this picture, was the smallest, with a diameter (measured under the microscope) of about .02 inches. The second smallest pinhole's diameter was about .03 inches; the next one's was about .04 in., and the largest one's was about .07 in. Lastly, I made shutters for the pinholes out of cardboard and attached them with black electrical tape. The picture to the right shows the camera soon after this point.

To take a picture with this camera, I would Scotch Tape a piece of film to the side of the box opposite the hole I wanted to use--so if I wanted to take a picture with the side hole, I would tape the film to the side facing that hole; and if I wanted the bottom hole, I would tape the film to the lid. This part was done in the darkroom, of course. Then I would take the camera to the place I was trying to take a picture of, aim the camera, lift the shutter while I counted seconds, and then close the shutter when I thought the film had been exposed enough. The next step was to develop the film, so I would return to the darkroom, remove the film from the camera and the tape from the film, then place the film in the developing solution, then the stop bath, then the fixing solution. Finally, I would rinse the film and take it out into the light so I could see what (if anything) I had created.

What Actually Happened

After building the camera, I started taking pictures using the smallest pinhole, the Kodak film, and the side hole. Since I had never used a pinhole camera before, I planned to take a few pictures with this setup to practice and to make sure I could, in fact, get a picture. My first two pictures, however, were completely black. Thinking that light could be getting in through the thin plastic lid, I covered the outside of it with the black electrical tape. When the black spraypaint began flaking off the lid's inside, I also painted a cardboard circle black and fitted it inside the lid. At Dr. Bordley's advice, I loaded the camera with film and took it outside but didn't actually lift the shutter to expose the film. I also used all three different types of film to determine if the film itself was the problem. However, the next six pieces of film I developed were still either fogged or completely dark. Then I put black tape on the bottom of the camera to keep any stray light from coming through there. I also guessed that the red-painted light bulb that was used in the darkroom was affecting the film, so I started working in the darkroom using only the very dim overhead safelight. When the next four pictures I developed were still completely black, I decided to repeat the procedure of loading the camera but not exposing the film, but keep the camera inside the lab. When I developed this film, it was only slightly fogged. From this result, I decided that my camera must be letting light in, so I covered the entire box with the black electrical tape. The fuzzy picture above and to the right shows the camera as it finally looked.

I took my next several pictures inside and was relieved when they were mostly clear instead of totally black. Dr. Bordley also bought a new box of Kodak film, since what I had been using was a few years old and running out. At last, aiming the camera at a window, I produced my first clear picture, shown to the left. On my twenty-second picture, having taken Dr. Bordley's advice and aimed the camera out of a different window, I suddenly realized, to my amazement, that the image on the developed film was a tree, with buildings at the bottom. This negative is shown to the right, with its inverse image, the actual picture (thanks to Adobe Photoshop 3.0), at the far right. With that, I was ready to begin the actual project.

The Actual Project

After having spent nearly two weeks making the camera produce pictures, I did almost all of the project's actual research--varying the variables--in two days. By the end of them, I had taken and developed thirty-one more pictures of the tree and buildings mentioned above and thoroughly hated the darkroom and the smell of photographic chemicals. For each picture, I aimed the real camera, with the f stop set at 11, out the window and recorded the light meter reading. I used this reading to make an educated guess at a good exposure time, aimed the pinhole camera, and took the picture. I developed the film by leaving it for two minutes in a solution with a 1 to 3 ratio of Kodak Dektol developer to water, then putting it in a stop bath solution for thirty seconds and a fixing solution for one minute. Along with the light meter reading, I recorded for each piece of film the exposure time, the pinhole used, and the position of the pinhole (bottom or side). I had already abandoned the idea of making another camera, and I ran out of time to use different types of film.

Results, In Theory

Judging from my pictures, when using a pinhole camera:

--As pinhole size increases, the size of the image increases, the amount of light reaching the film increases, and the detail of the image decreases.

--As the distance from pinhole to film increases, the size of the image increases, the amount of light reaching the film decreases, and the detail of the image decreases.

In theory, therefore, this is what should have happened:



	Smallest Pinhole	2nd Smallest Pinhole	2nd Largest Pinhole	Largest Pinhole
Shorter Pinhole-to-Film Distance (Side Hole)	Greatest detail and smallest image; Most underexposed using shorter distance	Detail, image size, and exposure between that of smallest and largest pinholes, but closer to smallest than to largest	Detail, image size, and exposure between that of largest and smallest pinholes, but closer to largest than to smallest	Least detail and largest image using shorter distance; Most overexposed
Longer Pinhole-to-Film Distance (Bottom Hole)	Best detail and smallest image using longer distance; Most underexposed	Detail, image size, and exposure between that of smallest and largest; closer to smallest	Detail, image size, and exposure between that of largest and smallest; closer to largest	Least detail and largest image; Most overexposed using longer distance



In Practice

Reality didn't work quite as neatly as the table, though.



• In judging the detail of a picture, blurring caused by motion obscured the effects of the pinhole size and pinhole-to-film distance.
• Over- and underexposure further obscured these effects.
• Fogging caused by accidental exposure to light veiled the effect of exposure time as well as concealing detail.
• Especially when using the longer distance (which requires more exposure time), keeping the camera still for the time required for a well-exposed negative was very difficult; thus, blurring from motion occurred often.
• Aiming the camera was guesswork.
• Badly-aimed pictures made comparisons more difficult.
• The light meter reading and the actual time required for a good exposure only occasionally appeared to be correlated (no thanks to the setting sun shining directly at the camera).
• The pictures taken with the longer pinhole-to-film distance did not appear to increase in size as the pinhole size increased.
  
  The last problem mentioned probably occurred because the small increase in size due to the pinhole variation disappeared within the much greater increase
  size as the image traveled twice as far to reach the farther pinhole. Some of the other problems, such as keeping the camera still, aiming the camera, and predicting a good exposure time, improved with time as I got more practice. The last picture I took (number fifty-four overall), shown to the left, was by far the best. I took it at about 11:30 a.m. using the Kodak film, the smallest pinhole, and the shorter pinhole-to-film distance (side hole) and exposing it for fifteen seconds. The sky was clear and the light meter, with the f stop at 11, read 125 (the real camera would have exposed the picture for 1/125 of a second). The actual negative looked better and clearer than the scanned image, but there wasn't too much I could do about that. The picture to the right is the inverse image of the negative, thanks again to Photoshop. Jason Payne made two Van Dyke prints of this negative, both of which look better than the inverse image shown here. To see them, go to his project's page. We were very happy about how well they turned out. In retrospect, I enjoyed working with my pinhole camera (after I made it work). If I have the chance to do so again, I'd like to take more interesting pictures, try to find a better way of aiming and keeping still the camera, find a better way to hold the film inside the camera, and take pictures with the film closer to the pinhole in order to get a round image. I hope the problems I encountered and solved help other people (like Dr. Bordley's future students) who also attempt to play with a pinhole camera.

Joy Reeves, 1997.