Camera Obscura

Project 4

15-463: Computational Photography || Alex Wolfe + Tim Sherman

Overview

For this lab, Tim and I created our own pinhole camera (as illustrated here by Jim Hayes 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 used a digital camera with an extended exposure time.

Creating the Camera

First Attempt

Tim and I created our camera out of a postage box that on a better day was filled with ramen and dried shitake mushrooms. Despite both being art students, we only had one sheet of black paper between us, so we gessoed the interior, painted it black with acrylic paint and attatched a piece of white printer paper as the screen. We then used an exacto to cut two holes, one for the camera and one for a swappable piece of paper with the pinhole pierced through

We tried using a small digital nikon at first, since it was small, portable, and I didn't mind having it completely covered in tape.

The disadvantage of conveience was that the camera only had about an 8 second exposure time max. Since our photographs were taken during a typical dreary overcast Pittsburgh day, this had terrible results that looked something like this.

Second Attempt

We decided to go get a bigger gun, and rented this beautiful SLR from the school of art. As well as being a much nicer piece of equipment, it allowed us to expose our images for up to 30 seconds. Also since I have excellent exacto skills, we created a tight enough fit that we didn't have to tape our eqipment up to avoid light spills into the camera obscura.

The Results | Series of 3 sizes

We then set up our camera and captured a series of images containing (relatively) the same scene using 3 different pinhole sizes, 0.1mm, 0.7mm, 1.5mm

Scene One

pin

med

large

Scene Two

pin

med

large

In both series, the larger aperture did significantly better than the other two. Since the day was slightly overcast, letting in the extra light was a huge help to developing a clear image.

The Results | Continued: Photographs using the 5mm pinhole

The larger pinhole actually took some decent photographs. How successful final image turned out to be were actually influenced by a couple other factors too.

Blurry vs. Sharp

We manually autofocused the camera using an LED light shining through the pinhole before each image, so some of the blurriness/after effects were due to the fact that I have ridiculously weak noodle arms that have never been used for any sort of physical labor, so pictures where the box was able to rest on the floor or a solid surface worked best. (or when Tim held the camera)

It's also easier to get a clear image if you're photographing an inanimate object that doesn't mind holding still for 30 seconds dispite windblown hair and an itchy nose.

Indoors

Indoors were were only able to get a decent image if the camera was pointed at an object that emitted its own light, regardless of the aid of the florescents and any windows. There simply wasn't enough illumination otherwise.

The Rest

Bells and Whistles

Light Drawings

These were made by waving an LED flashlight frantically in front of the camera for 30 seconds

Using a Lens instead of a pinhole

I collaborated with max for this particular bell + whistle, since we both had giant cameras, and his camera obscura was made out of a pumpkin, which isn't the most expensive rented equipment friendly. We couldn't get a clear image with this method though, despite focusing both the inserted lens and the digital camera lens. We probably didn't have enough light inside my studio.