Beautiful! - GELITA® Photo-gelatines in focus
Some 8.3 million digital cameras were sold in Germany in 2010. However, this does not necessarily mean that analog photography is no longer in use: on the contrary, it is experiencing a revival, as reported by Dr. Jörg Siegel, Managing Director of InovisCoat. His company is based on the production of film materials, including photo-gelatines from GELITA.
"Photography in a way is very similar to what is now happening in the area of multimedia. Here, the CD initially replaced records but now the vinyl discs are coming back to favor. It's the same with analog and digital photography", says Dr. Siegel, who spent many years with film producer AGFA. InovisCoat was founded in 2005 with the intention of utilizing AGFA's coating technology to develop and produce innovative photographic products. These included well-known products such as black-and-white films and paper and color-negative paper but also the less well-known instant photos for Polaroid cameras ("The Impossible Project") and innovative coating solutions for films, medical technology and safety products. "These of course are not mass-produced items but rather niche products for special areas such as instant photos", he emphasizes. This market is of little interest for large companies so that production facilities for certain film types continues to be closed down. However, for InovisCoat, the market is indeed of interest. They employ 25 people and small production lots are just right. "Small", however, can mean up to one million square meters a year.
No photo without gelatine
Regardless of how much movement is in the market, one aspect has not changed and, according to Dr. Siegel, will not change: no photo material is possible without gelatine. And, in the case of InovisCoat: not without GELITA® Photo-gelatine. "Right from the beginning we worked with gelatine from GELITA and were always quite happy“, says Dr. Siegel. Thanks to the technical know-how provided by GELITA our stringent quality characteristics have always been adhered to when we change batches.
But why is gelatine necessary at all for the manufacture of films and photographic paper? "It is necessary to have a matrix that binds the light-sensitive halogen iodide crystals.“ The decisive factor in developing films is the ability of gelatine to swell but then to dry. The fixed and dried gelatine on the carrier of the film being a hydrocolloid, it absorbs the developing fluid so that the photo pigments can form. Once the developing process has been completed, the paper is dried again. Gelatine is added during the formation of the silver halide crystals. Gelatine stabilizes these and influences crystal growth and form. In this way the light sensitivity e.g. can be increased: flat crystals of the same volume are more sensitive than cubic ones as their surface is greater. And, the larger the crystals, the more light-sensitive they are. "This interactive effect between crystals and gelatine is unique and cannot be replaced", says Dr. Siegel. And as this type of interaction can be transferred to other applications, important aspects of this photographic know-how are being used for the development of other innovative technologies with gelatine.
The question of course remains: just how does the photographic emulsion, the gelatine solution and the silver halide crystals get onto the film? InovisCoat utilizes a high-tech casting technique called "multicoating", a process that allows all the layers to be applied to the film in one step. In this process, the viscosity of the gelatine is a critical factor: if the gelatine has a specific predetermined viscosity, the layers will not mix. "Some artists apply the layers by hand in order to achieve specific effects; these, however, are not reproducible", according to Dr. Siegel. For film material, this reproducibility is important. Each type of film must show precisely the same properties; only in this way can photographers do a proper job. And only in this way can they produce beautiful pictures!
Dr. Christoph Simon
Telephone: +49 (0) 62 71 84-2535
christoph [dot] simon [at] gelita [dot] com