Camera Obscura and Camera Lucida

Philosophers and scholars such as Mo-Ti in the 5^th century BCE and Aristotle in the next century observed and described the phenomenon of light passing through a pinhole to produce an inverted image. Alhazen in the 10^th century further observed that the image being projected becomes sharper or softer based on the size of the aperture. The concept of the camera obscura, Latin for “dark room,” came about during the Renaissance to control this phenomenon of light passing through an aperture. “Daguerre's suggestion that art could achieve the goal [of reproducing images of nature without drawing] points to the fact that the camera obscura was a widely used drawing aid at the time. Therefore, photography could be seen as the climax of the development of drawing aids, which began in the Renaissance” (Gasser 12).

The camera obscura improved throughout the next few centuries as lenses sharpened the image and mirrors corrected the inverted image and projected it onto a more convenient surface for artists. The basic lens type used was an achromatic doublet with both convex and concave lenses. This cancelled out chromatic aberration, in which different wavelengths of light have different focal lengths. In a pinhole camera, the light passes through the aperture and projects onto whatever surface is beyond the aperture. With the addition of a lens, the light is transmitted and refracted at angles that will cause the light to converge and focus at a specific spot. This means that the surface the image is being projected onto has to be at that focal point, unlike a pinhole camera in which the location of the surface wasn’t critical. The use of a lens brightened and sharpened the projected image. This benefited both scientists and artists as it improved a device for “aiding graphic representation and for ascertaining basic truths about nature” (Rosenblum 192).

The interest of artists to accurately translate the visible world to a graphic representation led to the invention of other devices such as the camera lucida, Latin for “light room,” which was patented by William Hyde Wollaston in 1807. Unlike the camera obscura, the camera lucida doesn’t require specific lighting conditions and it doesn’t project an image. Instead it allows the artist to view the subject and drawing surface simultaneously. It is constructed of a prism and lens on a stand, but with the addition of a mirror, the image becomes right side up and is corrected left to right.

Gasser, Martin. “Between “From Today, Painting is Dead” and “How the Sun Became a Painter:” A Close Look At Reactions To Photography in Paris 1839-1853.” Image 33, no. 3 (1991): 9-30.

Rosenblum, Naomi. A World History of Photography. New York: Abbeville Press, 1997.

A camera obscura box with a mirror and a large walk-in camera obscura in San Francisco.

 

A diagram of a camera lucida.

The suggestion that Dutch artists Johannes Vermeer used a camera obscura to obtain the remarkable detail in his paintings remains controversial.

http://www.essentialvermeer.com/camera_obscura/co_one.html

For my camera obscura, I used a double convex glass lens instead of the plastic magnifying lens from class. Light traveling parallel to the lens axis passes through and converges at a spot behind the lens. The distance between the lens and this spot where the image is in focus is called the focal length.

To make my camera obscura, I used two boxes. Because one was bigger than the other by about an inch, I put extra cardboard in the bottom to make the smaller Life box fit. I cut off the ends of the Life box.

I cut a hole the size of my lens in the bottom of the larger box and taped the edges of the lens so it sat over the hole.

 

The focal lengths I found were 6.75in to 7.25in depending on the distance between the object and camera obscura so I cut the Life box down to 6.5in so the focus could be adjustable. I taped wax paper over one open end of the Life box.

I added strips of cardboard to the sides of the Life box to make pushing or pulling the box easier for focusing.

 Right-side-up image of plants in a pot.

 Right-side-up image of a pillow on a couch.

Making the camera obscura was a lot easier than I thought it would be. I’m glad I made it adjustable because it’s cool to be able to focus on distant or nearby objects. The focus is also sharper than I was expecting it to be.

Photographer Abelardo Morell works extensively with camera obscuras. He has used tent-cameras that project images of his surroundings onto the ground which he then photographs, and he uses small and room-sized camera obscuras with amazing detail.

He also photographed the crescent shape of a partially eclipsed sun projected onto the ground through holes in leaves, much like what Aristotle observed in the 4^th century BCE.