CS 194-26: Project 2

Building a Pinhole Camera

Karuna Wadhera, CS194-26-abo & Kimberly Zai, CS194-26-aca

Photos of our Pinhole Camera Itself!

To create our pinhole camera we just started with a plain old shoebox. We made sure to cover all sides inside, except for one, with black paper. On the last side, we placed a piece of white paper. Our image would form on this white piece of paper. On the opposite side, we created a small hole for our differently sized pinhole slips to cover. We used pinhole sizes of 1mm, 3mm, and 5mm. Next to that small hole was a larger hole for our camera to fit. We secured everything with duct tape in order to prevent any light from leaking in.

Trying out multiple pinhole sizes

In real life, thanks to the Sun, there's light all around us. Thus, light is reflecting off of objects from many different angles. With a larger pinhole, light rays from many more angles are entering, since the larger diameter size allows it. But because objects now have many more reflected light rays entering the camera, there are more rays (with different light wavelengths) contributing to each location on the image and the resulting image is not as clear.

Given this, understandably, our 3mm image was blurrier than our 1mm ones, and our 5mm one was even blurrier.

We also noticed that our images with larger pinholes were brighter. This also makes sense because a larger pinhole (aka a larger aperture) means that the total amount of light being captured during the same time duration is greater. In order to combat this, we changed the exposure time of the bigger pinhole to 5 seconds (instead of 30 seconds). This led to a much more reasonable image that was less bright. This difference is shown in the Doe library 5mm images.

It is also important to note that the captured images were upside down. We flipped them right-side up when we posted the images on this website. This is because the light rays reflecting from the top of an object would travel through the pinhole in a straight line, ending up at the bottom of the image plane. The same would happen for the bottom of the object, with the reflected light rays ending up at the top of the image plane. The following diagram is able to visually show this pinhole camera image effect.

Pictures with 1mm, 3mm, and 5mm Pinholes

Doe Library; 1mm
Doe Library; 3mm
Doe Library; 5mm (w/ 30 second exposure)
Doe Library; 5mm (w/ 5 second exposure)
From the top of the Campanile!; 1mm
From the top of the Campanile!; 3mm
From the top of the Campanile!; 5mm (w/ 5 second exposure)

Pictures with 1mm Pinhole

We decided that the 1mm pinhole size resulted in the best photos because it produced the sharpest image and had a reasonable compromise with brightness. Even though the images weren't as bright as the ones produced by the 3mm or 5mm pinholes, we thought they were still bright enough to make out the colors and key features of the photo.

Memorial Glade & East Asian Library
Valley Life Sciences Building
Hearst Mining Circle

Uncropped Picture

The images displayed here on our webpage are all cropped. We wanted to display one image before cropping so it's easier to visualize the raw images we were working with! The uncropped image shows the inside of the box. On the side with the white paper, the camera is able to capture the image due to the reflected light.

Before Cropping
After Cropping

Challenges Faced

Neither of us expected taking pictures with our pinhole camera to take so much time!

Finding a good place to take pictures was a struggle. Sometimes, the lighting wouldn't be good enough for our pictures to come out with the quality we'd like, there would be too much movement in a scene or there wouldn't be a ledge to keep the camera stable and we would have to try to stabilize the camera ourselves (which is NOT an easy task for a duration of 30s!).

For example, we tried to take pictures inside of the beautiful North Reading Room in Doe Library, but ultimately it was a dark photo in which you couldn't make out much of what the room looked like inside. You could definitely see the window and the outside world, though!

Finding the correct angle to tilt our pinhole camera was also tough because it wasn't like we had a "preview" screen in which we could preview the photo we were about to take.

For example, when taking the Campanile picture, we had to take many different shots until we finally found the angle we were looking for.

In the beginning, we also dealt with light leaks. We hadn't taped the camera at first, and this allowed some light to leak in from the corners. There were also light leaks from some smaller corners of the box and a small cardboard flap the shoebox came with.

We also had to manually re-focus our camera to focal length distance if we accidentally moved the focus (before we taped the camera).

Sometimes the camera would move as we clicked the button to take a picture, so we set an auto-timer of a few seconds to avoid this.

Bonus Picture! (Additional bells & whistles?)

We decided to jump into the small pool of water where the Hearst Mining Circle Rings were located and take a selfie! We used a self-timer to make sure we could get in the picture in time. It took a few tries to get it right, and we probably looked hilarious smiling without moving for 30 seconds, but it was worth it :)