Ambrotype

Ambrotypes were most commonly performed by unkown photographers. The process involves creating a positive photographic image on a sheet of glass using the wet plate collodion process. The wet plate collodion process however involves creating a negative image though James Ambrose Cutting created a way of doing so as a positive image. This was patented in 1854.

How to create an ambrotype

1. One side of a very clean glass plate is covered with a thin layer of collodion 

2. It is then dipped in a silver nitrate solution

3. The plate is exposed to the subject while still wet (exposure times vary from 5-60 seconds or more depending on the amount of light available.)

4. The plate is then developed and fixed

The negative that results from this when viewed by reflected light against a black background will appear as a positive image

5. one side of the glass negative is coated with a black varnish to create this effect (either the emulsion or blank side can be coated) this adds depth to the image.

6. another plate of glass is placed over the emulsion side to protect it

7. It is then mounted in a metal frame and kept in a protective case. 

The Ambrotype was much less expensive to produce than the daguerrotype and also lacked it shiney metallic surface. Ambrotypes were often hand tinted, untinted ambrotypes are grayish-white and have less contrast than a daguerrotype.