photogenic_drawing

This weeks lab had extremely different results than last week, the prints were actually visible with a reasonable exposure time!

Photogenic drawing, also known as a calotype, was first announced by William Henry Talbot in 1839. This process is very similar to anthotypes, but with the addition of silver iodide which greatly changes the results of the prints. The prints were first coated with varying amounts of NaCl and AgNO3 and then exposed outside under direct sunlight. After the prints were exposed, the silver iodide decomposes, and any that remains needs to be washed off. In the case of the class experiment, the prints were then washed in a salt water solution so that the image would "fix" to the paper.

After our experiment a few conclusions can be drawn from the different solutions of NaCl and AgNO3 that were used. The heavy weight paper used in our tests held up much better than lighter weight paper and resulted in better quality prints just because the paper didn't disintegrate. Another conclusion is that the stronger the solution, and the more coats of it, yielded darker exposures.