Introduction

The pinhole camera (also called the "camera obscura") is essentially a dark box with a pinhole on one face, and a screen on the opposite face. Light reflecting off an object is directed through the pinhole to the screen, and an inverted image of the object forms on the screen. The caveat is that it is hard to see the image formed with the naked eye.

To be able to see the image, we will use a digital camera with a long exposure time (~1-30 seconds) attached to the pinhole camera. The optimal pinhole diameter is 1.9 * sqrt(f * lambda), where f is the orthogonal distance from the pinhole to the target surface and lambda is the wavelength of light (~550 nm). However, in the follow case, the suggested 0.1, 3, and 5mm pinhole sizes are used.

Constructing a Camera Obscura

Materials Required:

  • Shoebox
  • Black Paper
  • Printer Paper
  • Scissors
  • Lots of Masking Tape
  • Lots of Electrical Tape
  • Digital Camera (Sony A6300)
  • For our project, we used a Adidas shoebox to provide a dark box for the target surface. Here are the steps we took outlined below:

      1. First, we took the lid off and cut a hole through one end of the box. The size of the hole should match the size of our digital camera lens.
      Next, we cut out a rectangular opening next to the first hole, where we will place our pinhole.
      3. We cut out 3 card papers the size of our rectangular hole and poked 3 small holes through each of the card papers. The diameters we chose were 0.1mm, 3.0mm, and 5.0mm. This way, we can easily switch the size of our pinhole by just attaching one of the three cards.
      After all the holes have been cut out, we cover the opposite end of the box (our target surface) with white printer paper, which will act as our film. Then, we cover the other sides of the box completely with black paper.
      5. We continuously peer into the lens hole with our naked eye to see if there are remaining cracks or holes that let light into the shoebox. We sealed the entire box up with black duct tape until there is no more light left when we peer into the hole. Now our camera obscura is ready to capture images!

    Behind the Scenes

    • Checking the focus

    • The camera in the box

    • Shooting

    • The holes

    Scene 1: Edgy Teen

    • Shutter Speed: 30s Aperture: 0.1mm

    • Shutter Speed: 1/3s Aperture: 3mm

    • Shutter Speed: 1s Aperture: 5mm

    Scene 2: Selfie Obscura

    • Shutter Speed: 30s Size: 0.1mm

    • Shutter Speed: 10s Size: 3mm

    • Shutter Speed: 10s Size: 5mm

    Reflection on Samples

    Initially, if there was good sunlight, the 0.1mm seemed the best for taking photos. The images are clearly more crisp and given more light, perhaps could've even resulted in almost perfect photos. But after taking all the photos, it seemed like 3mm had the best balance between color and clarity. Having a larger pinhole size seemed to result in a less focused picutre. As a result, 5mm was a little too out of focus as well as losing a significant amount of color clarity. Some examples of shooting extra 3mm photos are shown below. The results were significantly better than expected. We were even joking about how close these photos looked like polaroids. An easy next step was to try out long exposure light painting which ended up working quite well as shown below. But perhaps the most fun experiment we tried was making GIFs! We noticed that at 5mm, we could shoot at 1/10s for shutter speed which meant we could easily string together a short GIF. The two we shot are shown below as well.

    Other Images

    • Trees

    • Sky

    • Self Portrait

    • House

    Suggested Bells and Wistles: Light Painting

    • Fat Heart

    • Star

    • Infinity

    Extra Bells and Wistles: GIF Obscura

    • Look at my Boomerang I look soooo cool

    • I took Tae Kwon Do when I was in 1st grade

    Struggles

    Easily the biggest problem throughout was ensuring the digital camera was in focus. Since the lens used was a 30mm Sigma 1.4 lens, the lens actually had a focus by wire which means that the actual position of the rotated lens didn't correspond to the actual focus of the lens, even in manual. Therefore, every shot would somehow change the focus and we'd have to remove the camera readjust the focus letting in some light so the camera could focus on the paper and reshoot. Coming up with a clever way to handle that took some time but in the end we added an additional hole at the top to let light in when needing to focus and quickly autofocused and the switched back to manual to prevent further focusing.