Push processing

Push processing used in photography a development technique for deliberately under-exposed films.

Push processing is primarily used in black -white films, however, is also possible with color slide and color negative films. For this purpose, a film having, for example, ISO 400, such as an ISO 800 film and then exposed afterwards pushed with a so-called " 1 Development", in order to obtain correctly exposed images.

In push development to go with the increase in exploitable film sensitivity involves additional effects. In most cases, particularly with forced application ( 2 and above), Pushing has significant quality losses result in:

• The gradation curve is steeper, high-contrast scenes go both in the shadows and in the highlights details are lost, the representable subject contrast is reduced;
• It is increasing in general, the granularity through increased aggregation of developed silver particles;
• With color films will reduce the maximum density, so that actually appear black parts of the image in the projection dark brown or dark blue;
• With negative films on, an increased base fog, the Quälschleier.