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Since I learned to press the shutter on my dad's professional camera at age six, I've been curious about the history of photography. I was born into a world where easy-to-use digital cameras were the norm, and I wanted to understand how the art, physics, and chemistry of photography came to this point.
I decided to pursue a project to recreate one of the first forms of photography: exposing chemical photo plates using a view camera (1800s). The photo plates (top right) are the sensors. They're made of a photosensitive and pigmented gelatine mixture that is spread thinly onto a glass plate. When exposed through the view camera, the gelatin hardens in a pattern that mimics the image projected onto it.
I had to execute several tests to figure out the correct exposure time for different gelatine mixtures. Underexposing and overexposing mean that you lose detail in the image due to too much or not enough of the gelatine mixture reacting/hardening. The "correct" exposure is a happy medium where some parts of the plate mixture haven't reacted at all but other parts have.
Once I'd found the correct exposure time (which can be well over five minutes), I'd set up the frame and take a photo like the one below (taken at Pierce Point Ranch in Point Reyes, CA).
Results
Results
Negative (the exposure plate over a white background).
Negative is reversed to produce final photo.
The next step I would like to carry out on this project is developing a color photograph. This can easily be achieved by creating three identical exposures, each exposed with either a red, green, or blue color filter covering the lens. The three exposures, although black and white themselves, carry information about how much red, green, or blue is present in the image and can be combined in Photoshop to reveal a color image.
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