Photographic film

A photographic film, the photosensitive recording medium of a camera or a film camera. The term is derived from the original meaning of the concept of film as a thin layer on a different material.

Originally it was thought to film only the thin layer of photo emulsion, the surface of a photographic plate was coated. With the invention of celluloid and its use as a film support a change in meaning took place. Today is meant by a film with a photo-emulsion coated, transparent film of tri - acetate or polyester.

Film was the leading method of analog image recording, but was supplanted in most areas since the beginning of the 21st century of digital recording methods.

Footage

Footage the physical carrier of the film medium, ie a strip of photographic film in a defined recording format.

When footage is referred to, among other things:

• Raw film, that is unexposed film prior to use in the camera
• Exposed film before development
• Ready developed film
• Uncut movie
• Cut film (eg, the working copy of the director or Cutters )
• Cutting waste or unused sections of film
• Film archives, as a whole or in individual settings

Usually refers to " film " on the first available generation, ie with negative film on the camera negative, with copies on a cut version; in the context of a single movie to all and any used in its manufacture material; in the context of documentation and archives to a possible early, "authentic" version.

See also: Footage

Development

After the exposure of the film in the camera, the film must be developed. For standardized, automated processes and the processing of hand according to various recipes come into question.

When developing the latent (hidden) image is made visible. Nuclei formed by light in the photosensitive emulsion may be catalytically enhanced by the development process. On the more exposed areas grows more elemental silver, the stronger was the exposure. The result is a negative.

When reversal film, which is taken eg for slides, the so-called reverse development takes place within the framework initially also a negative development, as a black and white image. Subsequently, the developed film is exposed to diffused light, said during the recording has not been exposed silver salt is exposed. In the following color development with a particular color developing the resulting oxidation products of the developing agent form with the color couplers contained in the emulsion film, the three dyes of yellow, magenta ( purple ), and cyan ( blue-green). The resulting both silver development processes is now transformed into a bleaching bath again in the silver salt, which is removed at the same time a bleach- fixing bath or in a subsequent. Therefore remain only the dyes that produce the positive image on the basis of subtractive color mixture. As a last step, the film has yet to be fixed, if, as now standard practice, no bleach-fixing bath was used. Fixing removes the remaining light-sensitive substances, thus preventing darkening of the image under the influence of light.

Subsequent watering the remains of the chemical substances of the ( bleach ) fixer removed ( final rinse ) are.

For the final rinse water is often set to network resources in order to achieve streak-free drying. Finally, the film is dried in a drying system or by hanging.

Positive and negative

We distinguish:

According to the structure

• Black and White Film
• Multilayer color film, including the types of daylight and artificial light ( color balance )
• Special films: eg for infrared images, infrared film, X-ray film, aerial film, Äquidensitenfilm ( " Agfacontur Professional" ), opal film ( coated on both sides, and oversight image in a slide), traffic camera film

According to the type of processing of the light

• Negative film

• Reversal film ( slide film )

After sensitization

Packaging

Movies are available for different sizes of the recording format and in different lengths; while a number of packaging types are distinguished. Common formats include the 35- mm film ( mm film ) with a negative / slide format of 24 × 36 mm for 12, 24 or 36 shots, medium format, the types 120, 220 ( twice the length ) with aspect ratios of 4.5 × 6 cm, 6 × 6 cm, 6 x 7 cm or 6 × 9, next to Type 127 for 4 × 4 (1 ½ x 1 ½ " ) and the APS film. above the medium format are large-format cameras, but the fed not with roll film, but with sheet film be.

Widespread movie formats are:

• 120 roll film ( medium format photography )
• 35 - mm film (Film: normal film; in photography: small-and half-format roll film ),
• 16- mm film (Film: Thin film; in Photography: The half-size and micro- picture film ),
• 9.5 - mm film (Film: Thin film; in photography: miniature film) and
• 8 mm film (Film: cine film )

Obsolete film formats are:

• Roll film 220
• 70 - mm film (Film: Wide film )

Sensitivity

The films are available in different light sensitivities (so-called film speed ). With increasing sensitivity of this goes back the resolution of the film, since the light-sensitive crystals become larger and as so-called grain may be visible in the photo.

Higher speed films have a poorer color fidelity and loss of the contrast range. In addition, the sensitivity also increases the price. The sensitivity is measured in degrees DIN (German Institute for Standardization) and ASA values ​​(American Standards Association ). The DIN data due will be based on a logarithmic scale. A higher number means 3 to a doubling of sensitivity. The ASA values ​​is a linear series is based. The standard applies since the late 1990s in color negative film has a sensitivity of 24 DIN / ASA 200. Slide films are usually from 21 to DIN / ASA 100. Most 200 ASA slide films are coated 400 -ASA film, so that their buying visually and financially not worthwhile.

For several years, an indication of the film sensitivity is internationally standardized in ISO 5800.

Resolution

The resolving power of photographic films is indicated by the number just separate line pairs per millimeter. Since the photographic resolution by the contrast depends, choose black and white lines. Qualitatively it is also called coarse-grained and fine-grained films. It depends on the properties of the film, in particular of the sensitivity of the film material and the processing conditions. It is generally considered that a highly sensitive film has coarser granularity. Commercial miniature films have resolution of 40 to 150 line pairs per mm. In black and white document films significantly more resolution can be achieved, ranging up to 1000 line pairs per mm. This is not original at Films for pictorial photography, but very high-contrast films for the reproduction of documents which must be very carefully processed with special chemistry. Examples: Agfa Copex, 720 Lp. with negative image; Eastman Image Link Movies 5360/7360 and Kodak 2468 ( Manufacturer Eastman Park Micrographics now ), both sensitized orthochromatic, low-sensitivity direct reversal films, 900 to 1000 Lp. Pure Bichromatgelatinefilme solve more than 5000 line pairs per millimeter, such as RF Orwo 53 ( Holographiefilm ).

When scanning negatives and slides resolutions of up to 10,000 ppi can be achieved. When miniature film (24 mm × 36 mm) corresponds to about a resolution of up to 135 million pixels.

Decline by the digital photography and current market situation

Since the peak of photographic film sales, depending on the country in or around the year 2000 around the worldwide sales since 2004 went back radically, by more than 20% per year compared to last year. One end of this trend (as of 2012) is not yet in sight today. Depending on the market, the decline from 2000 to 2012 is about -94 % to -99 %.

Film market in Germany

In Germany the sale of photographic films to end users in 2000 reached a peak of 191 million units and a turnover of 660 million euros. By 2011, this market slumped to 14 million units or 45 million euros, equivalent to an average annual decline of -21 %. For 2012, a further decline of -20 % to 11.3 million movies, 37 million euros is expected. This corresponds to 5.9% of sales volume in 2000, so that would be the film market in Germany still at a significantly higher level than, for example, in Canada or the U.S. (see below).

Film market in the U.S. and Canada

In the U.S., sales of photographic film was 786 million units in 2000. In 2010 it remained 4.1% or 32 million pieces left. The average annual rate of decline in the years 2004 to 2010 was -34 % per year. For 2011 and 2012, a further decline of -38 % and -25 % are expected to be only 15 million shares or 1.9 % of sales in 2000.

In Canada, sales of 35mm color negative film roles took in the amateur market of 54.5 million units in 2000 to 991,000 units in 2011 from. Since 2004 sales each year fell by more than -25 %; 2009 by more than -50 %. Overall, this was a decline to just 1.8 % of the base. For 2012, a further decline to 643,000 piece is expected, this is a further decline of -35 % and to 1.2 % of sales in 2000.

Manufacturer

The number of manufacturers of photographic films is greatly diminished by the success of digital photography in recent years. By far the biggest consumer of photographic films is the film industry.

As of today (February 2012 ), these companies represent films for pictorial photography and partly also for the cinematography ago:

• Kodak (USA)
• Fujifilm ( Japan)
• Ilford ( UK), Black and White Movies
• FilmoTec ( Germany ), Black and White Films
• Adox ( Germany ), Black and White Movies
• Fotokemika Efke (Croatia ), Black and White Movies
• Foma (Czech Republic), Black and White Movies
• Impossible ( Austria ), Instant Films
• China Lucky Film (China)
• Shantou ERA movie (China)

Manufacturers only produce films for technical purposes ( X-ray films, document films, Aerial Films ):

• Eastman Park Micrographics ( USA, outsourced Kodak microfilm division)
• Agfa (Belgium )
• Hindustan Photo Film (India)
• Tasma (Russian Federation)