15-663 Project 5

Pratch Piyawongwisal (ppiyawon)

Building a Pinhole Camera

Overview

I built a pinhole camera from a cardboard box and took several photos using different pinhole sizes and a digital camera with long exposure time setting.

The Camera

Instead of a shoe box, I used a thrown away cardboard box picked up from package pickup window in the UC. I covered the inside with black paper, except for one face in the back with white paper. This face is the image plane where light from the scene will project onto.
Opposite of the image plane, I cut out a hole for the pinhole and the camera. The camera used to capture the image was Canon PowerShot S95.

Originally, the hole I made was too far apart from the camera. As a result, the camera was not able to capture the whole scene, so I made another hole closer to the camera. The focal length of my box was 28cm. The pinhole size was calculated using formula 1.9*sqrt(f*550nm) = 0.75mm which is approximately 0.1mm. So I used the following 3 suggested pinhole sizes: 0.1mm, 1mm, and 5mm.

Photos

I captured two scenes using Tv (shutter priority) mode, in which I can manually select shutter speed and the camera will adjust aperture size accordingly. I picked the minimum shutter speed supported by the camera which is 15s. As shown below, the photos taken with 5mm pinhole are brighter and have more accurate color intensity, while 1mm ones are darker but have more details.

Good Results

View from my apartment window
First Trinity Lutheran Church

Auto-mode Camera

Auto-mode Camera

1mm

1mm

5mm

5mm

* Note: The original photos was upside-down. I manually flipped all the images vertically. The dark regions were caused by the box lid and the black paper that got pressed after I had sealed the box. I should have positioned the camera a bit lower and closer to the center to avoid this.

Bad Results

It turned out that 15s was not long enough to capture very low light image with 0.1mm pinhole. So the captured images were just all black.


0.1mm Apartment

0.1mm Church

Below is the first photo I took with the pinhole being too far from the camera. I fixed this by making another closer hole and sealing the old one with black paper.


Bells and Whistles

Light Painting