Pinhole Photography

Introduction

Pinhole photography is lensless photography. A tiny hole replaces the lens. Light passes through the hole; an image is formed in the camera. Pinhole cameras are small or large, improvised or designed with great care. Basically a pinhole camera is a box, with a tiny hole at one end and film or photographic paper at the other.

Pinhole images are softer – less sharp – than pictures made with a lens. The images have nearly infinite depth of field. Wide angle images remain absolutely rectilinear. On the other hand, pinhole images suffer from greater chromatic aberration than pictures made with a simple lens, and they tolerate little enlargement.

Pinhole cameras are used for fun, for art and for science. Designing and building the cameras are great fun. Making images with cameras you have made yourself is a great pleasure, too. But in serious photography the pinhole camera is just an imaging device with its advantages and limitations, special characteristics and potentials. By making the best of the camera's potential great images can be produced. Some of the images could not have been produced with a lens.

Terms

Orthochromatic Paper - paper that is not very sensitive to red light and as such can be handled (loaded, unloaded, and processed) with a safelight (red light).

Panchromatic Film - film that is sensitive to all light and therefore must be handled in total darkness during its development.

Developer - an aqueous alkaline bath containing a reducing agent that converts the silver (I) ion in the photographic emulsion into metallic silver thus making the invisible latent image visible to the naked eye.

Stop Bath - an acid bath that stops the developer from further developing the image by neutralizing the base present; this bath also prevents the formation of brown stains from the oxidation of any alkaline developer on the print.

Fixer - a weak acid bath that dissolves the unexposed silver (I) halides from the emulsion and makes the image more permanent; if the unexposed silver (I) halides are not removed they will turn the image black over time due to exposure to light.

Water Wash - this step rinses the emulsion free of chemicals to prevent the image from turning brown and fading away.

Procedure

Room with normal light

1. Pick a pinhole camera and make sure the pinhole is covered.

2. Cut two pieces of cardboard the same size (make sure that they fit inside the camera).

3. Cut a window in one cardboard to fit the photographic paper (the cardboard should only overlap with the paper a small amount on three sides, the bottom, left and right sides).

4. Take the pinhole camera and the two pieces of cardboard to the dimly lit room, the room only lit with a safe light. (do not forget to wear gloves before go to the dimly lit room)

Room with red light only

5. Cut a piece of photographic paper to fit inside the cardboard, place it between the two pieces of cardboard, and then tape on three sides. (make sure the smooth emulsion or light sensitive side should show through the window)

6. Place the cardboard containing the paper inside the camera about 6 inches away from pinhole. The smooth emulsion or light sensitive side should be facing the pinhole. Tape the cardboard on the left and right sides to the can on the inside of the can.

7. Close the pinhole camera, tape the pinhole with electrical tape, and place the camera inside a black garbage bag to protect from the light.

Outside

8. Select an appropriate object outside to photograph. (do not forget to bring a stand or chair on which to place the camera)

9. Remove the camera from the plastic bag and place it on the stand or chair. The object should be six feet away from the desired object.

10. Remove the electrical tape that covers the pinhole without moving the camera.

11. On a sunny day, the picture will require 15-30 seconds for exposure. On a cloudy day, 1-3 minutes will be necessary.

12. Cover the pinhole again without moving the camera, and then put it back in the plastic bag.

Room with red light only

13. With gloved hands, remove the cardboard and photographic paper from the camera, and separate the photographic paper from the cardboard without destroying the cardboard. (The cardboard can be used again with the same camera.)

14. Immerse the paper face up in the developer and swirl the solution for 2 mins and then drain the paper for 5 secs before submerging in the next bath. (Note: A picture resulting from good exposure to sunlight will appear within 20-30 secs in the developer bath and not turn black all over.) If the paper turns black, there is no reason to continue processing it.

15. Immerse the paper in the stop solution. Continuously agitate the solution for 10-15 secs and drain the paper for 5 secs.

16. Immerse the paper in the first fixer solution. Frequently agitate the solution during the 1 min and drain the paper for 5 secs.

17. Immerse the paper in the second fixer solution. Frequently agitate the solution during the 1 min and drain the paper for 5 secs. (Note: If the paper is not adequately fixed, silver halides will remain on the paper. These halides will cause darkening on exposure to light. The paper may appear slightly bleached if left too long in the fixer solution.)

18. Place the paper in an empty tray and take it to a normally light room.

Room with normal light

19. Fill the tray with running deionized water. Dump and fill several times.

20. Rinse the paper under running deionized water for five minutes.

21. Place the paper on a piece of clean glass and remove the excess water from the paper with a sponge or squeegee.

22. Hang the paper to dry on a clothesline or place on paper towels, print side up.

Procedure for making a positive (photograph) via the wet method

1. With the negative paper in the wash bath in the dark, place an unexposed piece of paper in the same bath for 1-2 mins.

2. Remove the two papers from the bath. Place the negative emulsion side down, on top of the unexposed paper emulsion side up, on top of a clean support surface.

3. Rub a sponge gently over the surface of the top paper to swish air bubbles and excess water from between the sheets of paper.

4. Turn the overhead light on for 1 sec and then turn off.

5. Put the negative back in the wash bath.

6. Put the positive in the developer and process as described in steps #14-22 above.

Procedure for making a positive (photograph) via the dry method

1. Take a piece of glass and foam (contact frame) to the dark room.

2. Place the dry, negative paper emulsion side down on top of a piece of unexposed photographic paper emulsion side up, on top of the foam.

3. Place the piece of glass on top of the pile. Without moving the papers, secure the glass to the foam with clips.

4. Expose to white light for 5 secs and then turn off.

5. Disassemble the set-up.

6. Put the negative back in the wash bath.

7. Put the positive in the developer and process as described in steps #14-22 above.

Conclusion

White paper or faint image

• The paper may have been loaded backwards in the camera.
• The shutter was not open during exposure.
• The exposure time was too short.

Especially dark image or black paper

• The camera has a big light leak. Find the additional light sources on the camera and cover with electrical tape.
• The paper was inadvertently exposed to white light.
• The exposure time was too long.

Observations

From my experiment, the best time for taking a picture in sunlight is between 30-45 seconds.

This page was created by Mr. Sermpun Lhamlhak on 03/01/05 (modified: 3/9/05).