Photographic ImagesBy David G. McLean
Identify originals and detect fakes
Avid collectors add extensively to their collections and inventory of photographic images, including daguerreotypes, ambrotypes, tintypes, stereo cards, real photo postcards, magic lantern slides and photographic prints of unusual or historic subjects. Despite years of collecting and buying experience, even experts might purchase a fake tintype. To avoid that experience, do extensive research and homework. Begin your studies here. In this article, we'll discuss the originals first, then the fakes.
The first practical photographic process in which an image could be permanently captured was the daguerreotype, invented by Frenchman, Louis Daguerre in 1839. The daguerreotype was made from a sheet of copper coated with a thin layer of silver. After the silver was polished to a mirror-like surface, the sheet was exposed to fumes of silver iodide. The entire sheet (which was dry) was then placed in a camera and exposed to the subject. The exposed sheet was removed and developed over fumes of hot mercury which caused an image to form in the silver coating. These images were fragile and easily damaged by careless handling. Original daguerreotype were enclosed in small cases, sealed behind glass, to preserve the image and prevent the silver from tarnishing. Daguerreotype were made primarily from about 1840 to the mid-1850s.
A daguerreotype can be identified by the unique polished silver appearance. The image can only be viewed as a positive from a narrow angle of view (tilt the image from side to side and the image appears to change between positive to negative). Tarnished Daguerreotypes should never be cleaned or "renewed" by dipping in tarnish remover. Such treatment has been found to cause permanent damage to the image and increases the chances of future tarnishing.
The next advance in photography was made by an Englishman, Frederick Scott Archer, in 1852. Scott developed the collodion process (pronounced ka-loe'-dee- un) which was the basis for both ambrotypes and tintypes. Collodion was a liquid made from nitrocellulose and other ingredients dissolved in alcohol and ether. An ambrotype is made from a sheet of glass which has been coated with collodion and wetted in a silver nitrate solution. Quickly, before either the collodion or silver nitrate was dry, the wet glass plate was loaded in a camera and the exposure made. After exposure, the glass plate was processed in two chemical baths which developed and stabilized the image. The final ambrotype image can appear either as a negative or positive image depending on the light. If held alone with the light coming from behind (transmitted light), the image appears negative. By viewing the image with reflected light, however, by painting the back of the glass black or putting a black piece of paper behind the plate, the image appears positive. All original ambrotypes were displayed as positive images and should be found with painted backs or backed with black paper, cardboard or metal. Ambrotypes were used from about 1855 to 1865.
In 1856, Hannibal L. Smith secured a U.S. patent for a modification of the collodion process. Smith applied collodion to a metal plate instead of the glass plate used in ambrotypes. From the first, these plates were always made of iron (never containing tin) but somehow became popularly known as "tintypes." Photographic specialists refer to tintypes by the more formal names of ferrotype or melainotype.
The first step in making a tintype was to cover the iron sheet with a hard, glossy black or chocolate brown Japanese lacquer (japanning). From this step through development, tintypes were handled the same as ambrotypes-- coated with collodion, wetted with silver nitrate, exposed in the camera while wet, and developed. Tintypes, unlike ambrotypes, did not require a black backing because the underlying metal sheet was already darkened by lacquer.
The major advantage of tintypes over daguerreotypes and ambrotypes was that their images were much less fragile. Ambrotypes and daguerreotypes required protective cases. Tintype images, on the other hand, were durable enough to be given to the customer loose or in simple paper mats (Figs. 6-7). By making the case optional, tintypes could be sold for less money than daguerreotypes and ambrotypes. The sturdy tintype could also be sent through the mail which opened up a whole new market-- the traveler and tourist. Customers could be photographed in far away places and the image safely mailed to the folks back home. This made tintypes very popular especially with Civil War soldiers.
The collodion tintype era was from about 1860 to 1870. Boardwalk and arcade photographers continued to make tintypes well into the 1900s, but the process was not the same. By the 1880s, the iron sheets could be purchased with factory applied dry emulsions that eliminated the cumbersome wet-plates.
Tintypes and ambrotypes were made by an almost identical process and can often be difficult to tell apart mounted in their protective cases. One test is to hold a strong magnet against the glass cover. Tintypes, on an iron sheet, will be attracted to the magnet; glass ambrotypes will not. Another situation you may find occasionally is an ambrotype which uses a tintype for a black backing. Under these circumstances, there may be a slight magnetic attraction but, with a little practice, the differences are soon recognized.
Daguerreotypes, ambrotypes and tintypes are all unique, one-of-a-kind images. In other words, the same plate that was exposed in the camera was also the finished product. If you wanted 20 photographs of your horse, for example, the photographer would have to make 20 different exposures of the horse.
Modern photography, by contrast, can produce many images from one exposure. This is made possible by a two-part system: 1) film negatives, and, 2) printed positives. The film you load in your home camera is a negative film. The means the film records dark areas as light, light areas as dark. After the film is developed, light is shined through the negative on to a light sensitive paper. This paper develops into a positive image, the pictures you hold in your hand. You can make as many positive images you want as long as the original film negative remains in good condition.
Most reproductions of original collectible images involve some aspect of two-part modern photography. A single negative taken of an original can be used to print off the high number of images necessary to make reproduction profitable. If you understand the basic two-part photographic system, you have a head-start on understanding how the great majority of new and faked pictorial images are made.
The 100-plus years of recording photographic images has left a well documented history of practices and procedures. Methods and materials have evolved, become widely used, then become obsolete as new and better ways came into use. Unless the faker knows this history of materials and techniques, the fake will not pass close inspection.
This brings us back to the fake tintype that started this research. Looking at the image through a magnifier showed that the image was formed by a dot pattern (Fig. 10). This was not right. Photographs are a continuous tone image; that is, photographs contain a full range of grays as well as solid black and solid white. A dot pattern is evidence of a modern halftone--the process used in modern printing to create the illusion of grays--by clusters of dots. The closer dots are spaced, the darker the image; more space between dots results in lighter tones. How did a tintype supposedly taken during the Civil War acquire halftone dots? It had to be an image copied from a halftone image printed in a book or magazine; it was not an original image of the soldier.
Closer examination suggested that something else was not right. Remember that a tintype, like an ambrotype, is a negative image that only appears as a positive when viewed against a black background? Close study of this image suggested that it was not a negative image at all, but was a positive image. A little poking and probing peeled off the emulsion to reveal a creamy off-white color (Fig. 9), not the black or dark brown of an original tintype. Not only was the image faked, but the entire process was deliberately faked as well.
But you don't have to peel back the emulsion to test for fakes-- there is a simple, nearly non-destructive test you can perform. Place a small drop of denatured alcohol on the emulsion in a hidden corner or edge. Leave it for 60 seconds then blot any excess. Original collodion emulsion dissolves in alcohol; post-1880 gelatin emulsion will not be affected. The fake tintype I bought with the halftone dots was not affected by alcohol--one more proof of its recent age.
In view of these discoveries, I made it a point to return to the place where I had purchased my fake and take a closer look at the other images in the same display. There were eleven more "tintypes," all showing a positive image on a white background and the now familiar dot pattern. Four of these images were in glued-together paper mats (making it impossible to see the backs) and two, including the highest priced, were in authentic old half-cases complete with brass mats and cover glass. Curiously enough, all of the paper mats were identical in design with just enough soiling to make them appear aged. None were identified as imitations or reproductions. All were displayed, labeled and priced in a manner to suggest they were authentic antique images (Fig. 12).
Although I have not examined faked daguerreotypes or ambrotypes myself, they have been reported by others. An article in the November 1992 issue of Maine Antique Digest(MAD) discussed a faked daguerreotype portrait of Edgar Allen Poe. Poe portraits are among the highest priced American daguerreotypes; one sold at auction in 1973 for $9,250. Unfortunately for the would-be seller mentioned in MAD, the portrait had the same flaw as my fake tintype-- it had been copied from a book and carried the dot pattern of a modern halftone. Don't be influenced by where an image is offered for sale; there are probably as many fakes in plush auction rooms as there are at flea markets. There is no substitute for close, detailed examinations-- take nothing for granted.
Examining Photographic Cases
The first cases for early photographic images were made with wood cores covered by leather, cloth or paper. Covers were usually die-stamped with decorative geometric or artistic designs. "Union" cases refer to a hard thermoplastic composition first manufactured in 1854. The word Union does not refer to the Union Army but the manner in which the raw materials - gum shellac and wood fibers - were united under heat and pressure. These cases are sometimes referred to as "gutta percha," but that is inaccurate. Gutta percha is made from the sap of a tropical tree and was mostly used in the manufacture of electrical insulation and was never used in photographic cases.
The diagrams in Fig. 13 show the individual pieces of a case and how the pieces held an image in place. If you are being asked to pay a "mint" price, be sure all the parts are present. In addition to cases for single portraits, there are double, and even quadruple, cases made to hold portraits in facing halves. All the mats and frames in these multi-portrait cases should match each other (Fig. 14).
In their hundred-year plus existence, many miniature photo cases have become separated from their covers and only the bottom half of the case- containing the image - is present. I have seen examples where an enterprising soul has joined two separate half-cases together selling the images of a man and woman as husband and wife (or Civil War soldier and betrothed). With few exceptions, most cases have the same decorative design on the outside of both halves. If the designs on the case halves are different, or if the case has been rehinged, beware - you could be seeing a "made-up" case from two dissimilar halves (Fig. 15). Some common hinge "repair" materials include vinyl electrical tape, cellophane tape and even embroidery tape. With rare exceptions, original cases halves are joined with rigidly attached brass hinges.
David MacLean worked in and with photography for nearly 50 years. His background includes technical production as well as photographic marketing.
19th Century Photocases
The diagram below illustrates how most 19th century photographic images on metal and glass were mounted in period cases.
The top piece (A) is a gold plated protector. It is a thin decorative edging with a flexible apron extending down the sides. The apron is bent around all the other pieces and holds them together before the completed image is placed in the case. The next item (B) is a decorative mat of stamped brass. This is usually, but not always, followed by a glass sheet (C) which protects the image (D). Very choice collectors cases have brass mats that match the outside of the case. All three pieces (B, C, & D) are held together by the bendable apron of the protector (A). The completed image is ready to be placed in a case.
Photography Terms and Cameras
The terms below and the equipment shown will help you better understand this feature article on photographic images.
Dry Plate- a photographic plate that is dry, (not wet) when it is loaded into the camera
Emulsion- the chemical coating on the surface of a photographic plate, photographic paper or photographic film
Film- a transparent base coated with emulsion
Negative- an image that reverses the original values of a subject-- dark becomes light, light areas become dark (see illustrations).
Positive- an image that maintains the original values of a subject-- dark remains dark, light areas remain light (see illus below)
Wet Plate- a photographic plate that is wet with chemicals (not dry) when loaded into the camera
Cameras of the Daguerreotype era, ca. 1840-1855, were little more than wooden boxes (Fig. 1). There were no shutters; the photographer just removed the lens cap. The photographic plate was fastened in a wooden case or magazine (Fig. 1-B), and loaded from the back or side. Cameras were big and bulky.
Since each plate only produced one image, inventors came up with various ways to make copies. One solution was to build a camera with multiple lenses. The camera in Fig. 2 could make 12 postage stamp sized images on a single 7x5" photographic plate. After being cut out, the small images could be put in cases, mounted as jewelry or made into political pins.
To save weight and space, cameras of the wet plate era, ca. 1854-1880, were made to fold up. This made cameras smaller and lighter so they were easier to transport. Better quality lenses were now being made but exposures were still made by removing the lens cap. A typical folding camera is shown in Fig. 3.
In 1888, Eastman Kodak introduced a small camera that used a 100-shot roll of film. This film had to be loaded in a darkroom but by the early 1890s, roll film could be loaded under normal light by the ordinary person without special equipment. This began the "press a button- -wind the film" system. The most recent innovation in photography has been the increasing use of filmless electronic digital cameras.