Much like us, Film comes in many shapes, sizes and lengths. Different cameras use different size film. If you're looking to get started with film photography you may not know, or even be aware of, what you need.
This is a quick guide to the a few of the most common film formats, and does not go into great detail. There are many more weird and obsolete film formats than mentioned here. You can find out more at Camerapedia.

How do I know which film I need?

Your camera will need a specific size of film. You cannot use a 120 film in a 35mm camera, and vice versa.
If you're not sure, check your model on Camerapedia. If you're still not sure, ask us!

Colour, or Black and White?

It's a common misconception that old cameras can only shoot black and white. As long as you can find film for them, all film cameras can shoot in either black and white or colour, so don't worry about that.

35mm Film.

By far the most common size film available today.

  • It comes in a standardised canister, usually with 24 or 36 shots on a roll.
  • It can be loaded into the camera in daylight, no need for darkness.
  • It must be rewound back into the canister before unloading it from the camera once all your photos are taken.

Most film cameras from the following manufacturers take 35mm film:

  • Nikon
  • Canon
  • Olympus
  • Pentax
  • Minolta
  • Yashica
  • Ricoh

And of course many more. 

120 Film.

(Not "120mm" Film!)

Cameras which take 120 film are usually referred to as "Medium Format". The film is physically larger than 35mm film, and is also used differently.

  • The amount of film in a 120 roll is fixed, but the number of photos which can be taken varies depending on the size of the camera, usually between 8 and 16 shots. 
  • It can be loaded into the camera in daylight, no need for darkness.
  • Rather than having a canister, 120 film is wound from one spool to another inside the camera and does not require rewinding. It has a paper backing, with a leader on each end for loading and unloading.

Most cameras from these manufacturers use 120 film:

  • Mamiya
  • Bronica
  • Hasselblad
  • Rolleiflex

And of course many more.