Manufacture

• Film is plastic sheet coated in silver halide crystals. The larger the crystals, the more sensitive the film is to light.
  
  To cope with all lighting conditions, manufacturers produce film with crystals of different sizes, from tiny crystals to cope with bright light, to large crystals for use in low-light films, such as the ISO 6400 film.
  
  

Function

• ISO 6400 film has large silver halide crystals and is designed to be used in any light conditions, even at night. It is the most sensitive film in common use.
  
  

Benefits

• The large crystals in ISO 6400 film enable photographs to be taken in extremely low light. Rapid motion can be captured with fast shutter speeds where slower films will produce blurred images. Photographs can be taken in ambient light, without the use of flash, making non-intrusive photography possible in locations like churches, indoor events and museums.
  
  

Disadvantages

• Large grain sizes produce grainy images that lack detail and sharpness. ISO 6400 film is not readily available in shops. It cannot be used in bright light with long shutter speeds. Digital versions of 6400 film suffer from similar physical limitations.
  
  

Digital Considerations

• Digital cameras use the ISO scale to represent the exposure settings of the camera sensor. Instead of grain, digital images suffer from noise, minor errors caused by the electronic processing of the information. This produces a grainy effect, similar to traditional film, with a coarse texture and subdued colors.