After the film pack is inserted into the camera, the darkslide is automatically ejected, uncovering the top sheet of film and positioning the film for exposure.
When a photograph is taken, the camera's exposure control system determines the correct combination of aperture, shutter speed and (in cameras so equipped) flash.
During the exposure, the shutter opens to project the image through the transparent film cover sheet, creating a latent image on the silver halide emulsion in the negative.
After the shutter closes, the photo leaves the film pack. On its way towards exiting the camera, it passes between rollers, rupturing the pod within the border of the film. The pod contains reagent that is squeezed from it and evenly spread between the negative and transparent cover sheet.
Contained within the reagent compound are white pigment, opacifying dyes, alkali, water and polymeric thickener and other photographically active materials.
Once out of the camera, the exposed photo begins the development process. During development instant film goes through essentially the same chemical process as conventional wet-process photographic development. The difference with instant print film is that the chemical process all happens with a single solution, automatically.
In black and white images, the development process involves the migration of silver compounds to the receptor sheet from those parts of the emulsion that have not been exposed to light. Color imaging involves a similar migration of dyes from at least three different layers. In color photography the primary colors are red, blue, and green. Their complements are cyan, yellow, and magenta, in that order.
The current generation of Black & White Impossible film has a development time of approximately 10 minutes, the Color ones of approximately 40 minutes, but we are currently working on a faster emergence and development film.