A while back I bought a camera from eBay
, an old Kodak
Junior 1. Unfortunately it took 620 rollfilm which is now almost impossible to get hold of.
120 rollfilm is easy to come by; it emerged at the turn of the last century and evolved naturally to become the standard for medium format film. Kodak made 120 cameras until 1931, when they decided on a new film format called 620. 620 is so called because it was originally supposed to take 6 pictures, with film identical to 120 rollfilm.
620 is identical to 120, you see, the only difference being that 620 spools are slightly smaller. The film itself is the same size; the only difference is the spools, which have thinner ends of slightly smaller diameter. You can turn 120 film into 620 film with scissors and sandpaper, or a cheesegrater if you do not have any sandpaper. I know this from personal experience. It is also relatively simply to spool 120 film onto 620 spools, as detailed in one of the nodes below, although if you do not have a 620 spool you are all messed-up in the head.
Kodak rationalised the creation of 620 by arguing that the fractionally smaller spools allowed smaller cameras, although this was nonsense, the same kind of nonsense spouted today by the manufacturers of incompatible inkjet cartridges. 620 is in fact an early example of 'format rigging' - Kodak created the format in order to corner the world's market for cameras by forcing Kodak buyers to use 620 and thus to force everybody to use 620 and thus to force everybody to use Kodak cameras. This kind of thing, therefore, is not unique to the computer age (one supposes that companies argued about the sizes of wax cylinders, or player piano rolls, or the type used in printing presses).
620 was very popular until the early 1960s, at which point Kodak moved away from making cameras to concentrate on film; although they produced 620 as late as 1995, the format essentially died a death thirty years earlier, as no other major manufacturers adopted it. Consequently, 620 cameras - mass-produced folding models and Box Brownies in particular - are available on eBay and thereabouts for less than the cost of a round of drinks and a meal. Provided one is willing to grate 120 film such cameras can be used nowadays, particularly so as many produce 6x9cm negatives - massive when compared to the 35mm standard 2.4x3.6cm - which can be printed and cropped at 8x10 without any loss of detail.