ARCturus

Photographing the phenomena in the sky is possible without film and expensive cameras. The pupils themselves can make a pinhole camera out of cardboard. This simple and cheap method of taking pictures is accessible for everyone. Also a tightly closed container with a small hole drilled on one side can be used for this purpose (photo IH, Finland).

 

The aim: To assemble a pinhole camera according to the instructions and take photos of the sky and the environment with it.

Explorations: The idea of a pinhole camera is very simple. All you need is a small hole and dark space behind it and, if necessary, material that captures the photo.

The camera can be a small booth in the park inside of which the image, reproduced on the back wall through the hole on the opposite wall, can be viewed. The picture is upside down but surprisingly sharp. On the other hand, pinhole camera can be a box made of plywood the backside of which is see-through plexiplastic or glass. The upside down image of the view can be observed behind the camera. If the aim is to get a negative image on light sensitive paper, the box has to be light-tight and reopened to attach and remove the paper.

The aforementioned observation devices can be used by the whole class. During the use of ready-made devices the role of a pupil is that of a passive observer. Each pupil becomes an active participant when he or she alone or together with a partner first makes a pinhole camera, takes photos with it, and then processes them into printed or electronic form.

1) Cut both halves of the pattern of the camera that have been copied on cardboard and fold them as shown in the picture (the pattern of the pinhole camera is in smaller scale in the picture).

 

Before gluing, attach a piece of foil pierced with a needle behind the circular hole. There is a matching circular hole on the exterior. Carefully glue the seams and sharpen the edges. Fit the counterparts inside each other. The ready-made pieces of the camera are seen in the picture. The bigger hole is seen in the upper and the pinhole in the foil in the lower one (design and picture IH, Finland).

 

2) Light sensitive paper requires special treatment. To avoid visible marks on the processed pictures, the emulsion surface shouldn’t be touched with bare hands or pressed with any object. The piece of light sensitive paper that fits the inner backside of the camera has to be cut in a room that is dark or lit with red light used in photo laboratories. The piece of paper has to be held from the edges. On the backside of the paper, a rolled tape is attached and with it the paper is carefully attached on the inner backside of the camera. On the exterior of the camera a rotating flap is attached to cover the pinhole when necessary. The same thing can be achieved with a container bigger than the camera, which can be removed without touching the camera or shaking its platform.

After the foil is attached, the pieces of the camera are placed inside each other and the pinhole is covered with the flap or the camera is otherwise kept in the dark. The ready-made camera is a small object that will fit the palm of the hand. The photographing can start. In the picture, pinhole camera is ready to take photos (picture IH, Finland).

 

3) The camera is placed horizontally on a firm, stable platform. With a rolled piece of duct tape, the camera can be attached to the platform to ensure that it will stay put during photographing. There shouldn’t be any materials in front of the camera that will hinder the quality of the photo, or objects not meant to be in the photo, such as glass sheets, wire, or sticks. The camera can stay put for as long as several days depending on the target.

4) The negative is scanned and processed electronically as a positive. It is easy to show the picture to everyone in the classroom and share it out. These photo-processing procedures can be achieved through careful guidance and are best suited for older pupils.

5) Instead of a pinhole camera made of cardboard a round-shaped sealable container can be used. The interior has to be painted black. A small hole should be drilled on the side of it. The container is attached firmly on a wall or a pole. The light sensitive paper should be cut to be slightly bigger than the diameter of the container. The paper will fold to a gradual bend on the inner backside of the container. It is easy to change the paper between photographing sessions. In the picture, a metal container has been attached on a standpipe on the roof of an apartment building. The camera photographs solar orbits (picture IH, Finland).

 

6) * Solar orbit can be photographed for several days. For example, when the camera is facing west from afternoon until sunset, the camera will capture beautiful light stripes setting on the horizon according the latitude. On a cloudy day, the camera can be sealed with the flap or a container. The photo of the sunset is taken by the rooftop camera made of a metal container (picture IH, Finland).

7)  * The orbit of the midnight sun can be photographed as a one-night session if there is a possibility to travel to Lapland. The result can be a beautiful downward bending series of suns above the horizon.

8)  * The Moon’s orbit can also be photographed with this camera. Good and desired results may require several takes or the development of the device, but if the pupils are resilient and enthusiastic this challenging task will surely be a success.

Methods: Observation with ready-made pinhole cameras. Making of own pinhole camera according to the instructions. Photographing with self-made small camera. Photo processing.

Materials: Hardboard, plywood, plexiplastic, cardboard, pattern of the camera, foil, light sensitive paper, photo processing chemicals, attachment materials.

Discussion: The targets of the photos should be planned carefully. By trying different exposure times and taking photos in different weather conditions you can get the best idea of how the photo sessions should be arranged. If the students have made a camera of their own, comparing different adjustments of cameras can be used to determine the best way to take the photo.

Examining the results: The photos by the students will be put on display in the classroom and the results will be compared. The chose of adjustments and possibilities for improvement will be discussed. This will teach the student how to achieve the best result through rational decisions.

Tips: Linking the photo processing to the programme of art lessons will benefit both subjects.

Key words: Pinhole camera, image formation, photo development, photo processing

 

 

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