Taking Pinhole Camera Pictures with Kevin Arifin and Taylor Wong

Pinhole cameras (aka "camera obscura") work by directing light rays through a small hole into a light-proof box. Inside the box on the opposite face, an inverted image is formed; usually we would place photographic film on that face to capture the image, but for this project we use a digital camera instead (with a long exposure time of 30 seconds).

Here, we try different pinhole "aperture" sizes (0.5mm, 2mm, and 5mm) for our pinhole camera on two different scenes to determine the best pinhole size, and then try to take several more images with the camera at the best pinhole size. Let's take a look at our pinhole camera design.

The Model

To construct our homemade pinhole camera, we started with a standard cardboard box. We lined the inside of the box with black construction paper to limit as much as possible the reflection of light within the box; one side was lined with white construction paper, where the image is to be projected upon.

On the opposite face of the box, we cut a large circular hole to fit the camera lens; next to this we cut a large square hole, which is to be covered with a piece of black construction paper with a tiny hole punched into it (our pinhole!).

We then attached the camera lens-first onto the circular hole and sealed the gap with black electrical tape. Lastly, we covered all edges of the outside of the box with multiple layers of black electrical tape to ensure that no light gets in.

We use pieces of black construction paper poked with different pinhole sizes, secured with masking tape, and just replace it to get the different aperture sizes (0.5mm, 2mm, and 5mm). Here is Taylor changing the pinhole size.

Camera Settings

Focal length: 28mm
ISO: 400
F number: 2.2
Exposure time: 30s

5 mm

Let's start with the largest pinhole size, 5mm, as a baseline and see how the image improves or worsens as we change shrink the pinhole.

2 mm

We see a slight improvement in image quality of both landscape shots by decreasing our pinhole size to 2mm. We see a slight improvement in the sharpness because the reducing the pinhole size reduces the scattering of light from each point source onto our imaging surface. Another consequence of the smaller pinhole size is that less light passes through and the resulting image is not as overexposed.

0.5 mm

0.5mm was the smallest pinhole size we could achieve to produce a well-lit image while keeping a reasonable ISO (to limit noise) and exposure time (30s max). A smaller pinhole size lets in less light, making for a darker picture, but results in a less blurry image because the "circle of confusion" is reduced. With the smallest pinhole size, we see that we get the sharpest images, just as we expected.

For these images you might notice a reddish haze. We observed that this issue was exacerbated when sunlight shone directly on our pinhole card. We alleviated the issue by keeping the face of the box in the shade when possible. We believe that this was only an issue for the smaller pinhole size because making a perfect pinhole in construction paper is impossible-- the paper fibers on the edge of the hole cannot be cleaned up.

Additional Images

We capture four more images with our best pinhole size, 0.5 mm, which you will find below.

Light Paintings

We took advantage of the long exposure time to create some cool light paintings through our pinhole camera.

Meet the Photographers

Taylor and Kevin are both 4th years.