Who invented Carlo photography?

Carol photography, invented by British scientist Henry Fox Talbot, is also carrying out its own experiment of recording images with black box.

Introduction:

Invented by British scientist Henry Fox Talbot, he is also conducting his own experiment of recording images with black box. 1834, he soaked the writing paper in silver chloride, dried it, covered it with lace or leaves, and exposed it to the sun. As a result, like Wedgwood's experiment, all the silver salts that were not covered by objects turned black.

However, Talbot found two important improvement methods. First, soaking the exposed silver chloride paper in concentrated salt water can prevent the image from further blackening. Second, although the exposed image is a negative image (that is, the black part represents white and the white part represents black), he knows that the correct tone can be displayed by printing this negative image on another photosensitive paper with light. The oldest surviving photograph of Talbot was taken in 1835. At that time, carpenter L. Abbey made a small wooden black box for him and put photosensitive paper on it.

1840, Talbot improved his photography technique. He switched to silver iodide, and at the same time, he also used a developer, so that the exposure time was shorter, and the image was stronger through the post-processing in 184 1. He applied for a patent for the improved method and named it "Calotype process".

Method:

Negative; Negative; Negative; negative

1. Use the best writing paper, dip it in dilute silver nitrate solution under red light, then dip it in potassium iodide solution and dry it.

2. Paint a layer of silver nitrate and acid solution on one side of the paper with a brush, put the photosensitive paper in front of the fire to dry, and then put it in a light-proof box for shooting.

3. Expose in a black box for 1-3 minutes.

4. Put it into the silver nitrate and acid solution used in step 2 for development, but the water must be doubled to halve the concentration of the solution.

5. Fix with hypo solution, then wash with water and dry.

active

1. Soak another piece of paper in salt water and dry it.

2. Under the red light, brush a layer of silver chloride solution with a brush and dry it.

3. Cover the negative on the paper, press it with a picture frame, and expose it in the sun until a dark brown image is formed on the paper. (about 20 minutes)

4. Fix the image paper, rinse it with water and dry it.