Whole plate
|
6-1/2" x 8-1/2"
|
Half plate
|
4-1/4" x 5-1/2"
|
Quarter plate
|
3-1/4" x 4-1/4"
|
Sixth plate
|
2-3/4" x 3-1/4"
|
Ninth plate
|
2" x 2-1/2"
|
Sixteenth plate
|
1-3/8" x 1-5/8"
|
The earliest cameras used in the daguerreotype process were made by opticians
and instrument makers, or sometimes even by the photographers themselves. The
most popular cameras utilized a sliding-box design. The lens was placed in the
front box. A second, slightly smaller box, slid into the back of the larger box.
The focus was controlled by sliding the rear box forward or backwards. A laterally reversed image would be obtained unless the camera was fitted with a mirror or prism to correct this effect.
When the sensitized plate was placed in the camera, the lens cap would be removed to start the exposure.
The focus was controlled by sliding the rear box forward or backwards. A laterally reversed image would be obtained unless the camera was fitted with a mirror or prism to correct this effect.
When the sensitized plate was placed in the camera, the lens cap would be removed to start the exposure.
... The daguerreotype is a direct-positive process, creating a highly detailed
image on a sheet of copper plated with a thin coat of silver without the use of
a negative. The process required great care.
The silver-plated copper plate had first to be cleaned and polished until the surface looked like a mirror.
Next, the plate was sensitized in a closed box over iodine until it took on a yellow-rose appearance.
The plate, held in a lightproof holder, was then transferred to the camera. After exposure to light, the plate was developed over hot mercury until an image appeared. To fix the image, the plate was immersed in a solution of sodium thiosulfate or salt and then toned with gold chloride.
Exposure times for the earliest daguerreotypes ranged from three to fifteen minutes, making the process nearly impractical for portraiture. Modifications to the sensitization process coupled with the improvement of photographic lenses soon reduced the exposure time to less than a minute.
The silver-plated copper plate had first to be cleaned and polished until the surface looked like a mirror.
Next, the plate was sensitized in a closed box over iodine until it took on a yellow-rose appearance.
The plate, held in a lightproof holder, was then transferred to the camera. After exposure to light, the plate was developed over hot mercury until an image appeared. To fix the image, the plate was immersed in a solution of sodium thiosulfate or salt and then toned with gold chloride.
Exposure times for the earliest daguerreotypes ranged from three to fifteen minutes, making the process nearly impractical for portraiture. Modifications to the sensitization process coupled with the improvement of photographic lenses soon reduced the exposure time to less than a minute.
 |
| Parts of the Daguerreotype, ca. 1854. From left to right: Glass, Mat, Daguerreotype, Preserver, Case. |
 |
| the way. |
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