Four characteristics of film you need to know!


Parts of film:

Clear, flexible plastic support, called the base. 
This is coated by...
Microscopically thin emulsion which is a chemical compound of light-sensitive silver halide crystals suspended in gelatin (yes that gelatin)
Antihalation layer
Protective layer

Film Characteristics are:

Film speed


When film is developed, the silver halide crystals that were exposed to light form small black clumps of metallic silver called grain

Prior to this when film is exposed it forms an insvisible pattern of altered silver halide in the emulsion. 
This is known as a latent image.

Size of grain particles is relative to film speed. The lower the iso, the smaller the grain- often referred to as fine grain.

It’s important to note that while in general the higher the film speed- the larger the grain- not all film brands are created equal. Grain will vary.


Tones refer to the range of grays contained in an image. In general the slower the film speed, the larger the tonal range


The relative difference between light and dark tones.

Note: there are many factors that contribute to the contrast of an image.