CS 194-26: Image Manipulation and Computational Photography, Fall 2018

Project 2: Building a Pinhole Camera

Joseph Reid, cs194-26-aes

Lavanya Mittal, cs194-26-afc

Alan Nguyen, cs194-26-ags


The camera obscura, otherwise known as a pinhole camera, is a dark box with a pinhole on one face and a screen on the opposite face. A single entry point is marked on the box in order to prevent any extraneous light from entering. Thus, any light that is reflected off an object is directed through the pinhole and to the screen, creating an inverted image. It is difficult to see the image with the naked eye, so a digital camera with long exposure capabilities (15-30 seconds) is required to capture the image.


Our pinhole camera consists of black poster paper, standard white paper, and a shoebox. The shoebox's interior is completely covered in black poster paper, though one face opposite of the pinhole was covered by white paper in order to represent a screen. Next, a circular hole is cut in order for the camera to be attached to the box, ready to capture images projected on the screen. Lastly, all of the box's openings that would leak extraneous light were taped by more black paper.

Furthermore, a hole is created in the box in order to represent the pinhole. A slider is created with 3 pinholes that are relative to the optimal pinhole size formula: 1.9 * sqrt(f * lambda), where f is defined as the distance between the pinhole and screen, and lambda is defiend as the wavelength of light. At first we made the hole too small which let to very unclear images, potentially due to diffraction.

Because the pinhole was placed above the camera opening, we had to angle the camera up in order to get a centered image. Before tilting the camera, the captured images would only be of the top half of the scene. In addition, to make sure no light entered through the camera opening, we used a sweater to wrap around this intersection of the camera and the box. Below are some photos of our setup:


Below are example photos taken with the camera obscura with a pinhole diameter of: 1mm, 3mm, 5mm. A larger pinhole diameter would lead to a more blurry image since more light enters the box and is diffused. On the other hand, a smaller pinhole diameter would allow less light in, creating a sharper photo. However, a longer exposure time would be necessary for compensation of light. Additionally, the distance from camera to the screen was about 4 inches, but the minimum focal length of our camera was about 1 foot, which explains some of the bluriness.

Diameter: 1mm 

Diameter: 3mm

Diameter: 5mm

Diameter: 1mm

Diameter: 3mm

Diameter: 5mm

After comparing the images with the different pinhole sizes, we decided that the pinhole size that worked the best was the 1mm diameter. Below are additional photos taken with 1mm pinhole.

Bells and Whistles

Light Painting

By placing the pinhole camera in a dark room and letting the only light source be from a moving object, we can "paint" with light on the pinhole camera by using a long exposure camera. Below are some of our results: