Darkroom

As dark a room is called, which is absolutely light-tight, so no light can enter from the outside, but inside quite (artificial ) may allow specialty lighting. Such a space is used in the chemical photography as part unit from the photo lab or copy center.

• 2.1 Light mazes for ventilation
• 2.2 Light mazes in small tanks

Areas of application

Total darkness or restricted to light of a specific spectral range is required to work where is handled with light-sensitive materials, with a photographic emulsion. Here are light-sensitive black and white and color emulsions in question, which may be located on different carrier materials, such as on a thin film of polyester or cellulose, on glass, on a little thicker plastic sheets or film or materials and cartons.

The darkroom photo lab

Many light-sensitive emulsions are only sensitive to certain types of light, ie light of a certain wavelength. This has the advantage that you can use light to which the photographic emulsion is not sensitive, harmless. See also: light spectrum and wavelength.

The darkroom is by no means permanently dark. Rather, the darkroom performs the task of light use with absolute control.

In the case of unwanted uncontrolled ingress of outside light is also called " stray light ", " light ", " light intrusion ", " light leak".

Light traps and mazes light

To avoid that light enters through the entering the darkroom, one uses a light trap. A light valve consists in principle of two doors. It can also be black, heavy curtains. If one enters now this lock from the outside, closing the door behind him first, so that you have now taken in complete darkness inside the lock. Then you open the second door and can enter the actual darkroom.

Light mazes for ventilation

If you have a darkened room ( for many applications also reaches a so-called change bag), you also have to also ensure good ventilation, because in a tight space, the air is quite fast stuffy. To this end, one can incorporate a light-tight fan in windows and doors. For such applications, use is made of a labyrinth. It refers to a system multiple times at right angles redirected channels whose inner sides are painted black. Help The angulation, to avoid direct exposure to light. The black color prevents reflection into a penetrating light into the space of the darkroom. Thus, the dark room for fresh air is open, light can not penetrate, however.

Light mazes in small tanks

Such labyrinths can be found since the 50's on a small scale, namely in film developing tanks. The mazes are there to make the necessary chemicals for film processing solutions come to light-tight manner to the photographic materials. Development tanks are in the field of small-and roll film processing extremely popular. Characterized the duration of total darkness is reduced to the tank in the processing of the photosensitive material at the time of introduction of the material. The actual development can take place in daylight.

Illumination in the dark

At the time of working with emulsion-coated glass plates ( before the invention of miniature film and roll film ) had to develop the recording material in shells. There were light-sensitive emulsions were insensitive to red light. One calls these emulsions orthochromatic (as opposed to panchromatic). You could develop this recording material at red light and watch the progress of development in the nascent state.

Here there is a fundamental purpose of the darkroom: Because today's photo papers to which a negative is enlarged, in the case of black and white processing are also resistant to certain types of light, beginners can already watch those resulting from the chemical processing image impression and controlled by open in the shell is designed for longer or shorter depending on appearances, or by heating certain image locations separately, while the development is in full swing, or controlled by external light, eg by switching on the main light on the in-process image meets to produce a so-called pseudo - solarization. See also: photographic effect.

Color film processing

In the processing of color films, sensitized mostly for all types of light (wavelength), many of these control options fall away. Here use is made of the tank development, instead of the shells to use even in large formats. After all, the result during the formation may indeed not be easily viewed. There is also while working in complete darkness and with most hazardous liquids at risk of spilling it, which both the other chemicals contaminate baths, as well as large and ugly, hard -to-remove stains on clothing can cause. Even sensitive mechanical- electronic devices, such as the enlarger ( enhancer) or the dry press, are at risk thereof.

Digital darkroom

With the proliferation of digital photography darkrooms and photo amateurs lose popularity. The post-processing of digital images on the computer is also known as a digital darkroom. The term includes both the equipment used (scanner, computer, photo printer ) and the necessary image processing and image editing software, such as Scan programs, RAW converter, image management and image manipulation software, and effects programs.