So what is this? Well, it's my own invention to measure the relationship between the size of the photograph and the size of the camera that made the photograph. During the history of the camera, the designers have tried to decrease the size of the apparatus without decreasing the size of the picture it made. The use of a bellows was a big improvement, but also the frontroll design of the early 1890's played an important role in this. For example the No. 2 Kodak, which has the film spools behind the plane of focus, is a much bigger camera than the Boston Bull's-Eye which makes use of the frontroll design. Both produce the same size of picture, so it's easy to compare them, but how about the other models? The tiny Pocket Kodak of 1895 is a very small camera, but the picture it produced is tiny as well. So which cameras are just small and which ones are really an improvement? To be able to compare all cameras I tried to devise a way to measure the relationship between the size of the photo and the size of the camera. I compare the size of the picture with the surface size of the camera. The total surface size of the camera does say something about its bulk, so it is a method to measure the size of the picture in relationship with the bulk of the camera.
Instead of the total surface of the camera, I take the average size of one panel (total surface of all sides devided by six). This is based on the most basic form of a camera: a cube with equal sides, with a lens on one side and the projected image on the opposite side. In this theoretical model the size of the picture is the same as the size of the side. This is my reference point, which I call 100 % (photo / average side * 100%).
For example the cube above has sides of 2 inches by 2 inches. The photo it produces is equal to the back panel, 2 x 2 inch = 4 square inch. The total surface of all sides is 2*(2*2+2*2+2*2)=24 square inches. The average side is 24/6=4 square inch. The picture/bulk ratio is 4/4*100%=100%.
If the cube is twice as big, the absolute surface sizes change, but the relation remains the same.
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Below is a table with some results. The yellow colored cells are of cameras producing pictures of about 5 square inches. The orange cells are all 4x5 inch cameras. The blue cells is the original Daguerreotype camera made by Giroux.
The camera with the highest score is the most compact. 
The original Kodak wasn't much better than the Giroux camera, at least if you look at the relative picture/bulk ratio. The Falcon Kodak (not the No. 2 Falcon!) took about the same size of picture as the original Kodak (5 square inches), but it was a big improvement. The Falcon is much smaller than the Kodak.
The No. 4 Kodak box camera is a bulky machine and as you can see, the No. 4 Folding Kodak wasn't much better. The Boston Hawk-Eye detective was even worst, but the Flat Folding Kodak was a real step forward, just like the No. 4 Folding Pocket Kodak. |
