Teaching Materials - Exercise

Pinhole Photography

Name of Artist Educator: Chris Wong
Level:
Excercise Category: Technical exercise

How does a light-proof box with a hole and a sheet of photo paper capture images?

During the Warring States period around 2,300 years ago, Chinese philosopher Mozi mentioned in the Mohist Canons that “Inversion arises from a small hole at the intersecting point of lights; the hole projects a long image because of the hole.”
The pinhole camera, which is derived from the concept of the camera obscura (Latin: “dark chamber”), is one of the most ancient ways to take photographs.


Concept / Inspiration:

During the Warring States period around 2,300 years ago, Chinese philosopher Mozi mentioned in the Mohist Canons that “Inversion arises from a small hole at the intersecting point of lights; the hole projects a long image because of the hole.”

The pinhole camera, which is derived from the concept of the camera obscura (Latin: “dark chamber”), is one of the most ancient ways to take photographs.

 

How a pinhole camera works

How does a light-proof box with a hole and a sheet of photo paper capture images? Relying on the fact that light travels in a straight line, pinhole cameras work by letting light rays from an object through a small hole to project an inverted image on the opposite side of the box. The image captured at the back of the camera is inverted. In his book Problems, the Greek philosopher Aristotle also wrote about the concept of the camera obscura. In the 15th century, some painters used camera obscuras to help them outline their subjects. The most primitive form of camera obscura is a completely dark room with a hole in one side, through which an external scene is projected onto a surface inside.

Note 1: A small pinhole means a large f-number, which can reach up to f/100(the maximum f-number of cameras is usually f/32). Pinhole cameras have an infinite depth of field. That means no focusing is required and the entire image is sharp. But as the pinhole is very tiny, the image needs a longer exposure time up to several minutes. It depends on the design of your camera and is a process of trial and error. Pinhole cameras produce negative images.


Goals:

  1. To allow students to understand and experience the formation of photographic images by constructing their own pinhole cameras and developing photos in a darkroom. This will give them basic knowledge of the mechanism of photography, such as the use of aperture and shutter.
  2. To let students realize that photography is not always about high-end, expensive equipment – they can make a simple camera on their own and still take good photos.
  3. To increase students’ interest in photography through DIY and photo experiments. The workshop also helps them establish the habit of keeping a photography journal and motivates them to teach themselves.

Materials / Equipment:

  • A box
  • Sheets of brass shim (one for each camera)
  • Black duct tape
  • Black paint
  • Ruler
  • Needle
  • Cutter
  • Fixer
  • Developer
  • Photo paper
  • Water

Location:

Darkroom and outdoors


Workshop Description:

Part One│ Pinhole Camera Making (30 minutes)

  1. Use a light-proof box such as a paper box, wooden box or a rectangular biscuit tin. Paint the inside black.
  2. Create a square opening in the middle of one side of the box. Cut a piece of brass shim whose size is slightly bigger than the square opening. Then poke a tiny hole in the middle of the brass shim and tape it behind the square opening.
  3. Create a removable and reattachable flap with black duct tape that covers the pinhole. It will be the shutter of the camera.

(The construction of the camera can be a home assignment to be finished outside the class.)

【Image 1】
pin 1

【Image 2】
pin 4

【Image 3】
pin 2

【Image 4】
pin 3

(Photos courtesy : http://www.instructables.com/id/How-To-Make-A-Pinhole-Camera/)

Part Two│Photo taking with pinhole camera (3 hours)

1. Fix a sheet of trimmed photo paper (or negative film) onto the opposite side of the pinhole in a darkroom. Make sure the shutter is closed.  “Image 4”
2. Look for photo subjects and scenes in the campus. In their photo journals, students should note down the exposure time of each photo and the weather conditions when they were taken. During the exposure, students may hold the camera or put it somewhere stable. They will use the removable flap as the shutter.
3. After each photo is taken, students will go to the darkroom and develop the photo paper. Then, they will discuss the results with the instructor regarding the exposure time and possible improvement of individual images, so they can learn more about the characteristics of pinhole cameras and the composition of images. Please note that pinhole photographs are negatives.
4. Student sharing session.

Note 1: For the photo developing process, please refer to “Darkroom─ Developing Photo”.
Note 2: Students are encouraged to mark down the exposure time with different weather. It enables them to have better control of the exposure time later and hence the exposure result.

pin 5 pin 6

pin 7 pin 8


Expected Outcome:

Students are expected to explore different exposure time and composition by themselves. The instructor could explain theory at the beginning such as how to adjust the exposure time with different weather and environment. This could provide them with basic understanding and directions in the experiment. But it is students themselves to try out the accurate and ideal time. They could be more complemented afterwards.


Actual Outcome:

The most challenging part for students was to drill a square on metallic containers for an ideal result as they drilled it too big. During a sharing session in the middle of the workshop, some students mentioned that they were not satisfied with the composition or there was only a dark blotch on their photos. So, the instructor suggested them to improve their cameras and encouraged them to pay attention to certain focus when composing an image. Students can make several pinhole cameras of various dimensions and use them to shoot the same scenes for comparison.

One downside of this three-hour workshop is that it is too short for a comprehensive learning experience, not to mention the enormous amount of time needed for developing the photos. Therefore, the ideal solution would be to double the time or add one to two more sessions to the workshop, so that students would have more time to learn both pinhole camera and darkroom techniques. The instructor would also be able to teach more advanced techniques such as double exposure.


Work:

Sample works by instructor:

pin 9   pin 11

pin 12    pin 13

pin 10     pin 14

pin 15 pin 16

 

 

Student work:

pin 17 pin 18

The reason for the dark patches was overexposure or an overly large pinhole. Too much light was absorbed by the photo paper. Some other images were too small because the distance between the pinhole and the photo paper was not long enough.

pin 19 pin 20

pin 21 pin 22

pin 23 pin 24

pin 25  a

pin 26 pin 27

 

 

 


Student Feedback:

“It’s my first time to do self-made pinhole camera and darkroom exercise. These are unusual and interesting experience of photography. ”

“I now understand the basic photography theory and the photo developing process in darkroom.”


Reference Materials:

Worldwide Pinhole Photography Day

http://pinholeday.org/?setlang=en

How To Make A Pinhole Camera
http://www.instructables.com/id/How-To-Make-A-Pinhole-Camera/
http://www.lomography.hk/magazine/220872-05-58-pinholes-and-sprockets-making-a-film-box-pinhole-camera-tw