To experiment with the camera obscura principle and to get an understanding of what a camera is and how it works, we were asked to try making our own pinhole camera for Lab 1 of Professor Steve Mann's ECE516: Intelligent Image Processing course at the University of Toronto. I will walk through the process of my few attempts with both failures and successes—the full learning experience. Please look at the attached pdf for the full lab report.

516Lab1MindySL (1).pdf
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Supplies

The first attempt - small pinhole camera:

Supplies:
cardboard box
white paper
aluminum foil
scissors
tape

The second attempt - Pringles pinhole camera (edition: "more cleanly & artistically made")

Supplies:
Pringles container
black paper
electrical tape
parchment paper
scissors

The third experiment - big pinhole camera

Supplies:
cardboard box
white paper
black paper
aluminum foil
scissors
electrical tape

Step 1: Small Camera & Big Camera

The small camera was made with a 6”L x 6”W x 6”H cardboard box. The inside was lined with thick black

paper with the sides covered by electrical tape to prevent light from seeping through. The side parallel to the side with the hole was covered with white paper. Two holes were made on the other parallel side; one hole was made to fit the lens of a phone camera, and the other hole was covered with aluminum foil with a small hole that was made by poking a needle through it.

Step 2: Adjustable Camera

This camera was made with a Pringles container, small rectangular box, and parchment paper. The pringles container was cut to split at around two-thirds of its entire length. The longer one was then cut down the side vertically and taped with a smaller diameter, enough to fit inside the other tube. This extendable design allows for the ”zoom-in, zoom-out effect of a camera as the size of the images depends on the distance between the object and the pinhole. The video linked in this report will further demonstrate how this was made.

Step 3: Adding a Lens to the Aperture of Small Box

A magnifying glass acts as a lens, creating a larger aperture for the pinhole camera, allowed for more light in for brighter and potentially clearer images. The magnifying glass concentrated and focused light onto the white screen, improving image brightness and contributing to sharper details compared to a simple pinhole camera. As all the dollar stores were out of regular magnifying glasses, I bought magnifying reading glasses which didn't have a flat frame causing a bit of light to seep through where it was taped.

Step 4: Analysis of Results Based on Experiments

Through experimental analysis of comparing the small camera and big camera, some things could be observed. In terms of pinhole sizes, generally a smaller pinhole yielded a sharper image. However, if the pinhole size was too small, it also resulted in degradation of image quality. During experimentation, the optimal pinhole size for the large camera was determined based on a tradeoff between the clarity achieved with a smaller aperture and the potential fuzziness as a result of diffraction. The other observation made was that although both the big box and the adjustable box had obviously longer focal lengths, the aperture diameter did not vary proportionally. In general, a longer focal length and a smaller aperture diameter could contribute to more detailed images, although it may be dimmer. Therefore, larger cameras have greater detail and sharpness.