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Coloring black and white photos .. How to process photos .. Photography book

How to process photos
Coloring black and white photos

Conversion or color change: There are some chemicals in the market for changing the color in ready-made proportions. You can also prepare chemical solutions from their components. When we change the color, the metallic silver color that forms the black and white image is replaced by a colored body. Thus, to convert an image, the image must first be bleached and not re-developed. Chemical conversions do not color the silver parts of the image and the coloring intensity depends on the density of the main image. In the light parts of the image, the background remains white. The image must be fixed and completely washed before starting the process.

We mention below two formulas for changing colors and also mention the method of work. The first formula is available in the market under ready-made and pre-prepared materials, while the second formula requires the use of separate compounds.

Sepia converter: This converter gives significant brown tones thanks to bleaching with ferric cyanide followed by a bath to change the color with sodium monocaprylate.

The solutions to be used are:
- Bleach: 50 grams of potassium bromide 100 grams of potassium ferricyanide - enough water to make one liter.

- Sodium monosulfide color changing bath: 200 grams of sodium monosulfide - enough water to make one liter.

To use, mix 4 parts of these solutions with 20 parts of water.

Proceed as follows:

(1) Bleach the image in the first bath until it becomes very light brown.

(2) Wash it briefly under running water.

(3) Dip the image in sodium monosulfide solution for about one minute.

(4) Wash the image for 30 minutes.

Sodium monosulfide solution has an unpleasant odor, so use it only in a well-ventilated place and discard used baths. On the other hand, spare solutions, especially bleach, can be stored for a long time in the dark in tightly closed bottles.

- Color change by copper: The color change by copper indicated below can give colors ranging from hot brown to light red depending on the duration of immersion in the conversion bath. At first, we get a dark violet color that then develops towards brown and then tends towards red. The solutions to be used are as follows:

- Bleaching: 50 grams of potassium ferricyanurate - 200 grams of potassium limonate - enough water to make one liter.

- Copper sulphate conversion bath: 200 grams of potassium limonate - 50 grams of copper sulphate - enough water to make one liter.

The solutions must be mixed thoroughly before use and discarded immediately after use. The method of use is similar to the method of conversion using sodium monosulphate.

In all cases, the density and contrast of the original image have an effect on the final result. Density provides color saturation while contrast, especially in the sepia converter, has an effect on the color tones of the image, whether cool or warm. In general, low-contrast images give warm tones while contrasting images give cool tones.

The (advertising) effect
You will get these large, monochromatic areas reminiscent of advertisements from a very contrasting black and white print obtained from a negative image. Apply uniform colors to the selected areas either with a vaporizer filled with transparent ink or by covering these areas with pieces of colored transparent adhesive film.

Using a chemical converter:
This iron surface was a suitable subject for a sepia-converted image. The warm brown color of the image is reminiscent of contemporary architectural photographs and gives the image a sense of abandonment and nostalgia. I made it from a black and white image on good-looking bromure paper. I bleached the image, washed it with water and resurfaced it in a sepia-converter bath. This image is indestructible.

Dyeing paper and dyes:
Some bromure papers have a colored substrate and the white barium oxide surface is then replaced by a second colored layer. You can use fabric dyes to color your black and white images. In this case the dye colors the entire area of ​​the paper: the effect obtained depends on the nature of the dye, the duration of the immersion in the dye bath and the temperature. A whole range of effects and colors can be obtained this way. The method is the same for a piece of cloth

It is better to choose a cold color or dye because it is easier to use and reacts in about five minutes. Hot dyes can sometimes spoil the sensitive face.

- Hand coloring:
Hand coloring a photograph is a great skill, but with a little practice, you can achieve satisfactory results by either coloring the entire area of ​​the image or just parts of it. There are many methods, including watercolors and transparent colors.

- Watercolors:
It is a good method for hand coloring, but you must practice applying the color in one layer on each area. Matte paper is better suited for this because it absorbs the color quickly. On the other hand, a layer of gelatin on glossy paper is very absorbent, which requires reaching the desired degree of coloring from the first touch, otherwise you will get a poorly distributed color. With a little practice, you will be able to apply saturated colors by marking with intersecting lines the sections you want to shade. The brushes must be of good quality so that their hairs do not fall out and stick to the gelatin. It is recommended to put a little bit of the wetting agent in the water of watercolor colors to make it easier to apply them to the paper.

- Transparent colors:
Liquid colors are easy to apply to paper and are characterized by the possibility of applying them with successive touches. Unlike watercolor colors, they cannot be removed with water. But at least its density can be reduced by immersing the image in a solution of sodium carbonate diluted with water.

- Using a jet brush:
Solid colors give a beautiful effect when applied by means of a vapor brush. This difficult technique is mentioned on page 200.

- Hand coloring:
Hand coloring, which was popular before the invention of coloring methods, has become the modern method. This method allows you to emphasize some important areas of the image and by showing them you can either seek realism or on the contrary completely change the values ​​and main colors of the subject. Take for example a not very dense monochrome image, i.e. black and white or converted by sepia. Fix the image. On a support before starting to color. We can also use aniline colors or watercolors. Apply the color with a soft brush while increasing the density with repeated touches. When working on a part of the image, protect the rest of the parts with pieces of paper.