handling 120 film

It is amusing that today, 120 film is regarded as a professional medium that is difficult to handle. After all, for decades it was the amateur standard for snapshots, used without a second thought by even the most fumble-fingered. Nor are those days so long ago. In the 1950s, Frances's father was a keen photographer and had a range of cameras including 35mm, roll-film and quarter-plate. Roger's father took only snapshots and used a roll-film box Kodak.

The first thing you need to realize is that there is a lot less standardization than you might expect in 120 film and cameras. After all, most dimensions were not originally very important. There was a strip of backing paper with numbers on it, and a strip of film taped to that by one end. As long as the numbers were in the right place to appear in the little red window in the back of the camera, and there was film in front of the backing number, it didn't matter very much exactly how long the backing paper was, or exactly how much paper there was before the film started.

Backing paper

The red windows on different manufacturers' cameras weren't even in the same place, but by printing two or three parallel sets of each number, the film makers could ensure that the appropriate number would usually be visible. The bottom set is 6x9cm or 8-on-120; the middle set, 6x6cm or 12-on-120; and the top set, 645 or 16-on-120. The 8-on-120 numbers are the originals and many cameras used these for 16-on as well as 8-on: the number was wound first into one window, which was nearer the feed spool, then into the other.

So far as we have been able to discover, for its first 25 years or so, 120 wasn't even designed to give eight 6x9cm/2¼ x 3¼ inch exposures (2¼ x 3¼ inches is 57.15 x 82.6mm): it gave only six. The film appears to have been lengthened in the late 20s.

Red Window

The famous (or infamous) red window is most associated with box cameras, but it is used to this day on some of the lower-cost panoramic cameras. For 6x17cm, for example, depending on the position of the window, you may wind on to 1; then 4; then 7; then 10; or (more usually) to 3, 6, 9 and 12. Most newer or more expensive cameras have a movable cover over the window to reduce the risk of light-strike through the backing paper. Originally, the red window offered far better protection because films were not sensitive to red light anyway.

 

 

Then came automatic film counting... Initially, you had to line up the first number in a red window, after which it was automatic (all right, Rollei TLRs had a film thickness sensor). Later came the 'start' arrow, with an index in the camera body. Even then, there's a modest tolerance in one direction: as long as the first frame is on the film, it's not especially important whether that frame is an eighth of an inch (3mm) from the start of the film, or an inch (25mm). A bigger gap gives a safety margin and easier handling, but the wasted film costs more.

 

 

 

Auto counting

The arrow on the backing paper is aligned with the red dot (there's one on the other side too, but you can't see it in this picture), after which the back is closed and the wind on knob or crank operated until it locks at frame one. Release of the wind-on may be automatic (when the shutter is pressed) or manual (a separate lever).

There are many ways to line up the arrow: coloured dots, arrows on the camera body, or even cut-outs so the arrow is seen through a hole. You can generally work it out for yourself though you may have to use a scrap film to confirm your conclusions. Actually, you don't need a whole film: just the backing paper will be accurate enough. Close the back; wind on to 1; then open the body to make sure the film is in place.

The minimum length of actual film that is needed for eight exposures in the original 6x9cm format is about 75cm or 30 inches: this allows a one-inch (2.5cm) safety margin at each end, and a 3mm (1/8 inch) gap between eight 84-mm-long images, which is the longest normally encountered in the '6x9cm' format . In practice, most manufacturers use 80-85mm, 32-33 inches and a wider margin.

The length of the backing paper is about 5 feet or 1.5 metres, while the spool is about 65mm high (two and a half inches) and the flanges at either end are about 25mm (one inch) in diameter. There are notes about the 120 derivatives, 620 and 220, below. There's also a half-length 120 which is very rare outside Japan and may not exist even there, any more.

The film is 62mm (2.4 inches) wide. Allow for a bit of a rebate at each side to hold the film fairly flat and you have a maximum image width of maybe 57-58mm. Most camera makers go for 56 or at most 57 mm: as already noted, 2¼ inches is 57.2mm. But there are no limits on how long the image can be. Some of the formats are:

Nominal size

Actual size

Number of exposures on 120

Comments

645

56 x 40 to 44mm

15 or 16

The smallest format normally encountered on 120. The 15-on format is often used to give wider spacing between images.

6x6

56 x 56mm

12 

Originally designed for use with reflexes: a rectangular-format reflex without a pentaprism is very inconvenient to tip on its side. The first auto-counting cameras gave 11-on at this size.

66 x 44

66 x 44mm

10

Alpa-unique format masked down from 6x7 to suit coverage of Zeiss Biogon 38/4.5 (80mm circle of coverage)

6x7

56 x 68-72mm

10

The so-called 'ideal format' for enlarging onto standard paper sizes. Linhof's 56x72 is almost exactly the proportions of the old whole-plate size (a 3x enlargement). A very few cameras gave 9-on '6x7'.

6x8

56 x

9

Rare but enlarges conveniently onto A-size papers: ideal for magazine pages.

6x9

56 x 78-84mm

8

The original 120 size, usually contact printed for tiny album prints. The 56x84 format is the same 2:3 aspect ratio as 35mm.

6x12

56 x 110-120mm

6

The advantages over masked 6x9cm can be overstated, as film flatness is necessarily inferior. The 1:2 format is rather stubby as panoramas go: often better masked to 44x110 (1:2.5)

6x17

56 x 170mm

4

A rare panoramic format which some find too long and thin. Also involves reloading unconscionably often.

6x24

56 x 240mm

3

The longest, thinnest and probably rarest of the standard 120 formats.

Combine the variations in the film with the variations in the camera makers' opinions and the variations in formats, and the scope for confusion is considerable.

220 and 620

The 220 size is a double-length piece of film with black leader and trailer, but no backing paper. Obviously this precludes red-window counting (and requires a dual-range mechanical counter, right) but (and this is less obvious) it also requires a different positioning of the pressure plate to compensate for the difference in thickness between film on its own, and film plus backing paper. Some cameras have repositionable pressure plates and adjustable counters but most don't. The one on the lower right is in our KowaSIX: you slide it down and lift it out, then reverse it, yellow dot to yellow 12 (as here) or red dot to red 24.

It is often cheaper to buy and process two rolls of 120 than one roll of 220, so unless you need the convenience of the longer roll, this may be a better bet.

The obsolete 620 size is identical to 120 except that it is wound on a spool with a smaller core and smaller flanges: this allows the cameras to be made very slightly slimmer. Our own uncharitable suspicion is that Kodak introduced it (in the early 1930s) to tie people to Kodak film instead of other manufacturers' generic 120 or B2 film.

If you are dextrous enough (we aren't) you can re-roll 120 onto 620. The problem comes when we get to the bit where the film is taped to the backing paper.

 

Counter

 

Repositionable pressure plate

loading the film for processing

In order to process the film, you have to separate it from the backing paper.

Work in complete darkness, obviously, and handle the film only by the edges -- though if your hands are clean and dry you can get away with touching the film, at least as often as not, without leaving fingerprints, and the very ends (the last 1/2 inch or 12mm or thereabouts) shouldn't be in the image area anyway. Obviously the non-emulsion side (outside the curl) is less sensitive than the emulsion side (inside the curl).

 

Break the seal

Start to unroll the paper

 

Soon you will come to the film. Do not worry about fingerprints on the very end: there should be no image here

Continue to unroll the backing paper, letting it fall away: the film will roll up of its own accord. Here the emulsion side is up, on the inside of the curl.

 

When you come to the tape that holds the film to the backing paper, carefully tear it. It is possible (though not easy) to tear the film at this point.

With a steel spiral, tuck the taped end into the centre. Fix it with the clip. Practice with scrap film: it is easy to kink the film and get stress marks.

 

Guide the film gently into the grooves from the centre outwards, holding it very slightly bowed as shown.

With a plastic spiral, re-roll the film the other way and feed the non-taped end into the outside. Again, do not worry about fingerprints on the very end of the film.

 

With a Jobo spiral like this, there are cut-outs for your fingers. Paterson spirals use 'snake-tooth' ball bearings for the same purpose.

Using your fingers alternately in the cut-outs, rotate the flanges relative to one another, feeding the film in. With Patersons you don't need to use your fingers like this: it's automatic.

 

 

With Jobo spirals you can roll the first film tight into the middle and then load another one outside it. With Patersons you cannot. But Paterson centre cores are light-tight; Jobos require a light-tight spindle like this.

Put the film in the tank and close and seal the lid and you are ready to process the film in exactly the same way that you would 35mm.

development times

You may note that some developers give different times for 35mm and 120. This can be for at least three reasons.

First, the formulations of the 35mm and 120 emulsions may be different. It's not particularly common, but it does happen.

Second, those writing the instructions may have assumed that 35mm will be printed with a condenser/diffuser enlarger and 120 with a pure diffuser. The latter lowers contrast, which can with advantage be boosted at the development stage.

Third, the bigger grain and lower sharpness that you get with increased development times are more of a drawback with 35mm than with larger formats. All exposure and development choices are compromises, and different compromises suit different formats.

Ultimately, of course, you will do best to determine your own exposure indices and development times, and there is a free module on ISO speeds as well as paid modules on choosing films, monochrome exposure, film developer choice and development regimes.

 

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© 2006 Roger W. Hicks