Some pinhole photography links: |
Pinhole Photography |
"How To" Article |
Pinhole Photography Pinhole cameras have been in use since the 1400s. Paolo Toscanelli built one of the first pinholes in 1468, though not specifically for the purpose of photography. From this construction, scientists determined that pinholes could reflect images, and the first cameras of this world were produced. Today, pinhole cameras are still used for many purposesmost often for studio, landscape, and architectural photography. Though pinhole cameras can be used for these purposes, regular cameras, which have some advantages over pinholes, are more commonly used. You can observe the differences between pinhole photography and regular photography by making your own camera out of ordinary household objects. Building and Using a Pinhole Camera: 1. Take a small cardboard box or tube and drill a hole in the center of a side. Use an exacto knife or a steak knife to clean out the "fuzzies" around the inner hole. Although a little too small, my best pinhole camera was made from a 3" by 3" by 2" jewelry box. (Smaller boxes and tubes are more likely to keep the light out. However, if the "camera" is too small, the pictures will have to be smaller as well.) · Steps 2-6 are meant for a tube camera, which will make your pictures "zoomed in" and dream-like. If you use a box camera, skip to Step 7 and make sure that no light can get into the box except through the drilled hole. If there are light cracks, use electrical tape to cover them. 2. On cardboard, trace the outside and inside of the tube twice to make the lid and bottom for your "camera." 3. Glue the two sets together, centering the smaller piece on top of the larger piece. 4. Fit the dry lids into the ends of the container. The tightest fitting lid will be the top of the "camera." 5. Remove the lids from the container and run a ring of glue around the bottom lid and secure to one end of the container. Wrap the seam in electrical tape to prevent any light from entering. 6. "Hinge" the top lid by running a single piece of electrical tape across the top. Attach one end to the "camera," and run a second piece of electrical tape across the tube horizontally to keep the lid from being pulled off. Fold the end of the first piece which is not currently taped to the container so that a small section of the sticky sides touch. Attach the rest of the tape to the container to hold the lid down. The folded tape mentioned above will serve as your handle. 7. Using a needle, punch a pinhole in the center of a one-inch aluminum square (from an aluminum can). The smaller the hole, the sharper the image appears on the film. 8. Tape, with electrical tape, the edges of the aluminum square to the "camera," with the pinhole centered over the hole drilled in Step 1. 9. To make a shutter, run a piece of electrical tape (about 3" long) horizontally across the pinhole. Fold one end to make a pull tab and secure the other end with a piece of tape running vertically. 10. Now you are ready to load your camera with photographic paper film, which can be bought at any photography store. Remember, every time you are loading, unloading, or even preparing your film, you should be in a light-tight darkroom. (A room with no windows makes a good darkroom; however, light cracks will exist. Simply put duct tape across those cracks.) A red light, which is safe to use with photographic paper, is the only light that you should use. 11. In your darkroom, cut photographic paper into approximately 3" by 5" squares. Handle film only on the edges, preferably in the corners. Each square will later be a picture, so cut as many pictures as you want. 12. Load film in camera on the opposite wall from the pinhole. The sticky side should be facing away from the wall, towards the hole. 13. Securely close the lid you removed to insert the film and make sure that the shutter is also secured. It is now time to take a picture. Stand approximately five feet away from your subject, remembering that your camera has a panoramic (wide) view. Exposure time depends on the individual camera. Typically, 10-15 seconds in sunlight and 20-25 seconds in cloudy weather works well. Inside photos take about four minutes. Set camera on a steady surface and aim the pinhole at the object. Pull shutter back and hold it away from the pinhole to keep it out of the photo. After exposure, securely close shutter and keep camera in a dark place (such as an unused drawer or closet) until it is time to develop. To take another picture, unload the photographic paper and reload the camera (in a darkroom). The developing for the pinhole photography is the same as it is for regular photography, except that the photo is already on photographic paper. For specific directions on the developing process, check out "Photography" in Compton's Interactive Encyclopedia or the Oatmeal Box Pinhole Photography webpage at http://www.nh.ultranet.com/~stewoody/darkcam.htm. Pinhole History: In fifth century BC, the basic optical laws of the pinhole were reported in Chinese texts. Chinese writers had detected by experiments that light travels in straight lines. The philosopher Mo Ti was the first to document the formation of an inverted image with a pinhole or screen. Mo Ti realized that objects reflect light in all directions, and that rays from the top of an object, when passing through a hole, will produce the lower part of an image. However, he did not actually use a camera. (GSP 5) In the Renaissance and later centuries, the pinhole was chiefly used for scientific purposes in astronomy and, tailored with a lens, as a drawing aid for artists and amateur painters. In 1475 the Renaissance mathematician and astronomer Paolo Toscanelli placed a bronze ring, which is still in use today, with an aperture in a window in the Cathedral of Florence. On sunny days a solar image is projected through the hole onto the cathedral's floor. At noon, the solar image bisects a "noon-mark" on the floor. The image and noon-mark were used for telling time to the half-second. (GSP 5) How the pinhole works: Pinhole photography illustrates the two primary descriptions of light. Sometimes it acts like a stream of particles, and sometimes it acts as if it were a wave motion: Light travels in straight lines. When it is reflected off of an object, each point of that object reflects rays of light in all directions. Some will travel towards the pinhole camera and a small cone of light rays from the point source will enter the pinhole. If the pinhole is small enough it will restrict the size of the cone of light rays so that an image of that portion of the object can form on a light receptive surface inside the camera (The Penultimate Pinhole Page). The Difference: There are both advantages and disadvantages to using a pinhole camera rather than a regular camera. Pinholes do not form images as sharp as those formed by a good glass lens. Also, they cannot be made to correct chromatic aberrations. This means that if a color photograph is made with a pinhole camera, the colors will be somewhat out of line with each other. However, this can also happen with a regular camera, but it is rare. A pinhole image is also dim, so longer exposures must be made. Pinholes do have an infinite depth of field. That is to say, although the resulting image is softly focused, all points in that image are equally in focus. Since there is no curved glass which we find in typical 35mm cameras, pinhole cameras are free from spherical aberrations. This means that a straight line will always appear straight, if one does not use a round camera. To understand the difference in how a pinhole and a lens form an image, imagine one point on an object some distance away. Light is reflecting off of and spreading out from that point in all directions, and in effect is forming millions of overlapping images everywhere. A lens takes in all of the rays of light from that point which enter into it and bends them, focusing them back down to a point on the film plane. (GSP 3) Like the original images in our eyes, this picture will be upside-down as shown in Figure 1. A pinhole does not focus an image. It acts more as a filter. It limits the light which reaches the film to a single path for each subject point. The paths are straight lines, so the image is inverted top to bottom and left to right. Ideally, a pinhole would be so small as to let in only one wave of light for each subject point. This would be true if not for the wave properties of light, which cause the light to diffract and the image to deteriorate as very tiny pinhole sizes are approached. Therefore, each object point is seen by the pinhole as a bundle of waves, which spread out from the object to the pinhole to the film cone. This creates a circle of light on the film, instead of a sharp point like a lens forms. This circle determines how sharp the image is, both in size and optimization. (GSP 3) Advantages and Disadvantages: Consistency is impossible with a pinhole camera. There is an element of surprise and randomness: I've always been excited to see just what my pinhole camera will do, with a certain amount of help from those sources beyond my conscious faculties, for I never fully know what's going to be in the image - there's the surprise I look forward to! It seems I am somehow closer to my own person by allowing the image to be something over which I don't have full control (Eric Renner). The pinhole camera naturally produces three types of photographic effects. The first effect is due to the longer exposure time. Pinhole cameras will not recognize moving objects. If a dog walks across your photo range while you are talking a picture, obviously there would be a dog in the picture. However, there would be no dog in Figure 9, because the dog would not have been there long enough to expose the film and show its image. Therefore, it is important for the camera to be set on a stable surface during the exposure and for the subject of the picture to be very still. Landscapers can use this to their advantage. If they need to take a picture of a landscape or building, they can do so without worrying about objects such as people or animals getting in the way of the photo. Secondly, the edges of the photograph receive less exposure than the center "creating a perfectly graduate vignette at the edges" (The Penultimate Pinhole Page). This can be seen slightly in Figure 7. Finally, the focal length is greater at the edges of the photograph, making the center appear "zoomed" in on (See Figure 9). The characteristics give the sense that one is moving through the scene photographed. This seems to produce a picture close to what one would see in a dream. (The Penultimate Pinhole Page) Pinhole photography may not have all of the advantages of regular photography, but it also has some benefits of its own. If you are interested in photography, need a science project, or would just like to increase your knowledge on an interesting conversation-starter, you may want to try this out. In any case, it can only help you see the world from another frame. Works Cited Kentucky Governor's Scholars Program (GSP). Pinhole Photography. Northern Kentucky University: 1999. "Photography." Encarta Encyclopedia. Version 96. CD-ROM. Redmond, Washington: Microsoft Corporation, 1995. Renner, Eric. Les Gehman's Photography Page. On-line. EZLink Internet Access. 5 Dec. 1999. Http://www.ezlink.com/~lpg Turner, Steve. The Penultimate Pinhole Page. On-line. Airtime Internet Resources. 3 Dec. 1999. Http://www.airtime.co.uk/pinhole/history.htm and Http://www.airtime.co.uk/pinhole/aesthet.htm |
Please excuse the disorganization in the Works Cited Section. For some reason, I can not change this. Thank you for your understanding. |
Some pinhole photography links: |
