After the film pack is inserted into the camera, the darkslide – a piece of card protecting your film from light – is automatically ejected, uncovering the top sheet of film and positioning the film for exposure.
When you take a photo, the camera's exposure control system determines the correct combination of aperture, shutter speed and (in cameras that have them) flash to get the best photo.
During exposure, the shutter opens, projecting an 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 is ejected out of the film pack, passing between two rollers. These rollers rupture a chemistry pod filled with reagent at the bottom of the film frame, spreading the reagent evenly across the negative.
Contained within the reagent compound are white pigment, opacifying dyes, alkali, water and polymeric thickener and other photographically active materials.
Once it’s ejected from 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 automatically, with a single solution.
In black and white images, the development process involves the migration of silver compounds that have not been exposed to light on the negative sheet, to a separate receptor sheet. Color imaging involves a similar migration, but uses 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.
Polaroid black & white film currently has a development time of approximately 5-7 minutes, while our color film develops in approximately 10-15 minutes, but we’re constantly working on creating the next generation of film, with faster development times, quicker emergence and sharper images.
Read more about How actual Polaroid film is different from the past.