What is difference between 120 size film and 220?

I have tentatively concluded that 220 gives twice as many images as

120 and needs a different back in some medium format cameras. Is this

actually the case? Are there any other significant differences between

them? In particular, is there any significant reason to use one

instead of the other??? Thanks in advance and apologies for asking

what is probably an obvious and elementary question!!!

<p>You're right: you get twice as many images on 220 than on 120: while 120 has a paper backing for the entire length of the film, 220 only has the paper backing at the beginning and end of the roll. Sometimes the actual thickness of the film base is different, but usually not.</p>

 

<p>Since 220 lacks the protection of the backing throughout the length of the roll, it can be more susceptable to light leaks. The only reason to use 220 over 120 is to get more shots between film changes.</p>

 

<p>Be aware too that not all films are produced in 220: few black and white films are available in this format, for example.</p>

There is another reason to use 220 film. It reduces the number

of rolls you have to carry and manage on a trip. If I'm away a

couple of weeks shooting perhaps a thousand frames, then 220

is a big advantage.

 

A disadvantage of 220 is that it's harder to buy- even on those

films made in that format. It is also discounted less than the

popular 120 emulsions so film cost/ frame is generally higher.

220 film is invaluable for using one of the rangefinder medium formats (Fuji or Mamiya models for example) as street shooters. Unlike a medium format SLRs (Hasselblad et al) switching formats in these cameras merely requires the manipulation of the pressure plate in the back of the camera, which in turn tells the camera which format is being used. Otherwise you always seem to be reloading just when the going gets good. The best inexpensive 220 shooting camera I know of is the Yashica Mat-124G, a really great TLR (6x6) camera with a sharp lens & solid meter that easily switches between 120 or 220 film. Unfortunately, 220 format film is unavailable in Czech Republic where I live, and it seems difficult to get in other European countries, so my Yashica got traded in on a 50mm for my Leica. Oh well.