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Sequence viewing > Index - Alternative Photo Emulsions - Resource - ©
Lloyd Godman
Alternative
Photographic Processes - (Hand
made photographic -emulsions and processes)
Processes
- daguerreotype process
Daguerre Daguerre was a scene painter at the Paris
Diorama. He experimented with capturing a permanent image from the mid
1830s onwards. Initially he had difficulty in persuading others of the
commercial merits of his process. However, an announcement of his daguerreotype
process was made on 7 January 1839. This was an image on a silver-plated
highly-polished plate. The image emerged when the plate was immersing
the plate in mercury vapour. Early experiments with the Daguerreotype
process took much longer to produce the image, using only the light
of the sun. Was the use of mercury vapour to speed up this process perhaps
discovered accidentally? The About Photography web site gives brief
details about Daguerre and his Daguerreotype process. Professional Photographers
The Daguerreotype process required expertise. It was used almost exclusively
by professional photographers. Photography was, in practice, restricted
to that class of society that could afford the high prices charged for
daguerreotypes. Process The daguerreotype process required the use of
mercury vapour, which led to a high mortality rate amongst the early
practitioners. The Daguerreotype process as described by Daguerre in
his pamphlet, The Daguerreotype, and in later pamphlets. The process
consists of five steps: 1. Clean and polish the plate. 2. Coat the plate
with a film of iodine 2. Expose to iodine fumes to create silver iodide.
3. Expose the plate in the camera 4. Bring out the picture. This is
done by Exposing the plate to mercury vapour in a Mercury Box to bring
out the image. This causes a layer of mercury vapour to be deposited
on the areas of the metal plate that have been exposed to light. 5.
Fix the image. Sometimes, the image is also gold toned. 1. Clean and
Polish the Plate - Take a well-prepared plate without blemishes - Fix
the plate by cement to a smaller wooden block - Hold the wooden block
in the left hand, and dust lamp-black over the plate. - Rub over the
surface of the plate with a velvet buff. 2. Coat the Plate - Take a
box made of glass or porcelain, with a well-fitting glass lid. - Pour
a solution of iodine into the box. - Attach the plate to the underside
of the lid and put the lid on the box. - Allow the plate to be coated
with iodine until it turns a golden yellow colour. Inspect with a candle
[Too short and it will remain pail and not be sensitive. Too long and
it will turn violet and cannot be used.] 3. Expose the Plate - Place
the plate in the camera taking care to protect from light. - Expose
the plate. 10 to 60 seconds exposure is usually required. © A Compound
Iodine and Bromine Box 4. Bring out the Picture - Support the plate
at an angle of 45% in the upper portion of a box. Mercury Box ©
This box is coated hard black varnish on the inside. The upper portion
of the box has a lid and glass front to allow inspection. The glass
is covered by a sliding door or curtain to keep out the light. The lower
portion of this box has a small porcelain or sheet metal cup to hold
mercury, and a thermometer to measure the temperature of the mercury.
The box is supported on legs above a spirit lamp. - Light the spirit
lamp © to apply heat to the cup containing the mercury. Heat to
140 degrees F (never more than 170) then remove the lamp. - Observe
the picture through the glass, and when the temperature has fallen to
113 degrees F, remove the plate from the box. 5. Fix the Image - Support
the plate at an angle of 45% in a flat porcelain dish. - Pour cold distilled
water over the plate. - Wash with a weak solution of hypo-sulphite of
soda. - Tone the Plate (if desired) by placing the plate on a brass
stand THEN covering with a solution of chloride of gold THEN applying
heat with a spirit lamp THEN pouring off any surplus liquid. - Wash
with warm water. - The plate is now ready to be mounted, to be preserved
from dust and damp. [Source: Photogenic Manipulation, published in 1843.
Chemicals for the Daguerreotype Process Below is a list of chemicals
for the Daguerreotype process, taken from the catalogue of Bland &
Long published in 1856. Please click on the list below for further details.
© Please click here to see Complete sets of Daguerreotype equipment
Result © A daguerreotype photograph is a faint negative image,
but with good detail, on the copper plate. The appearance changes with
the angle of viewing and can look positive from some angles, and can
barely be seen at all from other angles. The image is reversed, left
to right, so clothing appears to be buttoned wrong way round. Daguerreotypes
were normally mounted behind glass in small hinged cases with velvet
lining.
http://www.edinphoto.org.uk/1/1_early_photography_-_processes.htm
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