My 800ft (single spool) widescreen version of 'Grease' on super-8 film arrived today from the UK.

I had not seen super-8 film before. It's fiddly stuff.

What intrigued me though was the fact that the perforations run down one side of the film only.

Between each frame there is a black bar.

It struck me that if the perforations were put horizontally along between each frame instead of vertically down one side, one could achieve a more stable picture and make better use of the film in that more width could be devoted to the image.

THe trade-off of course would be that the film would be a bit weaker along where the horizontal perforations are located but a way to reinforce this strip could be found.

Was a gauge ever developed and impleneted which exploited the full width of the film by placing the perforations horizontally?

cheers Peter

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This is one area where the smallness of 8mm worked to its advantage: the film was so narrow and lightweight that dual-perfs were unnecessary. The film traps were usually quite long so there was pressure applied to both sides of the film quite a number of frames before and after the aperture. Also, all of the film traps in my 8mm projectors were designed as a kind-of channel that the film travelled through (instead of open-sided film bands like in some 35mm projectors).

As I recall, it was plenty steady...especially being an amateur format.

The other was something about farming and the film was also run vertically but the image turned via prism to a widescreen configuration. I have no information on how that one was shot.

The projectors were Century's modified with custom gates, traps and sprockets. Film handling was via an endless loop device atop the machine. Sound was 35mm mag interlocked running over an endless loop tree. In the case of the circus film, hole punches in the mag triggered other effects in the room.

Mark G. did some maintenance on these. It seemed to me that if 35mm mag was running on a loop tree without a problem for sound that picture could be handled the same way and I suggested converting to conventional 35mm 4-perf but with a vertical scope configuration for much better picture quality. But the 65mm EK had been lost and only the 3-perf 16mm IN was still around.

16mm camera stock is available in double or single perf, designated '2R' or '1R'. Single perf camera stock is so called 'B' winding, if you hold the roll with the film unwinding clockwise, the perforations will be on the edge furthest away from you, the opposite to a normal 16mm print, which is 'A' wind.

Most cameras can run single or double perf stock, the main exceptions being super 16, which must obviously be single perf, and a few cameras, mainly high speed ones, or very old ones, which can only run double perf.

8mm film was originally made by taking double perf 16mm stock, but with perforations at half the normal pitch, running it through a camera exposing images down half the width, then turning the roll over, and running it through again, exposing images down the other edge. After processing the film was slit, and the two halves joined together. There were a very few cameras which took film of the same format, but already slit to 8mm width. Just about everybody now calls this format 'standard 8', but I don't think Kodak ever used this term. Magnetic sound was later applied to this format, using a narrow stripe outside the perforations, with an advance of 56 frames, the same distance as the 28 frames on 16mm. I did once see a few frames of VD optical sound on standard 8, but I think this was experimental, and was never commercially introduced.

The disadvantage of standard 8 was that the perforations were disproportionatly large, so in 1965 Kodak introduced 'super 8', with smaller perforations, and larger frames. Provision was made for a magnetic stripe on the right hand edge, the opposite edge to the perforations, for a mono sound track, and for a slightly narrower balance stripe outside the perforations. silent speed was set at 18fps, with two sound speeds available, the standard 24fps, or 18fps, which many sound cameras ran at, for reduced cost. Some projectors were made which could record and play sound on the balance stripe, e.g. to add a commentary to an existing film, and later stereo sound was introduced, using the main stripe for the left channel, and the balance stripe for the right. Of course, like any other two channel system, this could use Dolby stereo matrix encoding for four channels.

In the '70s, optical sound was introduced on super 8, but was not very widely used, it was mono only, using a single bilateral VA track, in the same position, and about the same width as the main magnetic stripe. These tracks were dye, magenta and cyan, I think it would have been very difficult to re-develop a track so narrow. Normal white light tungsten exciters were used, but I don't know about the spectral sensitivity of the cells used. The sound quality of the optical tracks was not as good as the magnetic ones, but could be better than might be expected, but the printing of the track, and the alignment of the sound head is extremely critical, and the slightest speck of dust in the optics can almost oblierate the track. The system was probably seldom heard at its best. The airlines did make use of super 8 optical sound for a while. Magnetic stripes on 8mm are about the same width as the surround channel stripe on 35mm four track. Magnetic sound on super 8 is recorded 18 frames in advance, and optical tracks are printed slightly more than this, but I cannot remember the exact number. I don't think any lab is still recording, or printing, super 8 optical tracks today.

There were a few super 8 cameras which used double run rolls of film 16mm wide with super 8 perfs down each edge, the so-called 1-4 format. Super 8 prints were sometimes made in the same format, but more often in the 1-3 format, where both prints on the strip ran in the same direction, or in the 35-32 4R format, where 4 prints were made at once on 35mm stock, all running in the same direction. The prints being made for Derann today are printed in the 1-3 format on 16mm stock. They were printed by Rank until a few years ago, when this lab became 35mm only; I'm not sure who prints them now. Derann do the striping, recording and slitting themselves, using sound masters on 16mm fullcoat.

Centre perforations were used on a number of formats, the best known being the Pathe 9.5mm, introduced at about the same time as 16mm, and very popular at one time, but more so in mainland Europe than in the UK or US. Today, about 40 years after the demise of Pathescope, it is still possible to buy 9.5mm camera stock, and there are active societies of 9.5mm film makers, at least in Britain and France.

In the early days of the 20th century there were several other centre perf formats, mainly on 17.5mm nitrate stock.

One final point to bear in mind with 8mm and 16mm, they were both designed for amateur use, with reversal film, where the original camera film was projected. In order to do this, the film had to run through the projector with the emulsion towards the lens, and the base towards the lamp. This geometry became standard for prints made in both these gauges, the opposite to normal 35mm and 70mm practice. Internegs for 16mm and 8mm printing were either optically printed, or made on CRI, to give the correct geometry, but a contact print from a 16mm camera neg will be non standard. This will reduce the sound quality, unless the sound optics can be refocused, some projectors do allow this, and magnetic stripes have to be applied on the emulsion side, which can be done, but tends to cause problems.

Incidentally, optical sound tracks on Super 8mm film were able to be developed sparately. Since labs printed their Super 8mm prints on 16mm width film (with Super 8 perforations) the configuration had the sound tracks running side-by-side in the middle of the film. This way the developing was done for a track exposure that was twice as wide as the normal Super 8mm track width. After developing, the print was slit to produce 2 Super 8mm prints. As you can imagine, given the difficulty ok keeping sound track developer out of the picture area of 35mm prints, it was not easy but it was done. These prints were typically used in cartridges for in-flight entertainment before the days of Betamax and VHS.

Magnetic-striped prints were often printed on 35mm wide film. After developing, 3mms were slit off the sides, and the 32mm film was then slit down to produce 4 Super 8mm prints.

-Claude

Yes the 9.5mm format is kind of what I was driving at although the idea would be to use 8mm width with the centre perforations.

Using the full width (save for a sound stripe or two) would give an image width of a bit less than 8mm (7.6mm?). When one considers that (according to your link above) 16mm sound has an image width of 9.65mm, it is evident that the performance would approach that of 16mm film. With two sound stripes it would have superior sound as well.

In addition, the use of 7.6mm of the 8mm film, for image area would result in at least a 20% increase in picture width over super-8.

Further if one turned the image on its side with a 16:9 frame shape with horizontal frame pull-through the image size would be further expanded thus giving a frame width of 13.5mm which is better than 16mm film gives.

cheers Peter

The points you make in favour of a centre-perforated 8mm film are those that were made by Pathescope when they introduced 9.5mm, in 1923. It is true that this would give a larger frame size, it is often claimed that 9.5mm is close to 16mm, but if you compare the two gauges side by side there is a considerable difference. There is a saving on width of film, but a wider frame bar is needed to accommodate the perforation, so a greater length of film is required. The perforation pitch of 9.5mm film is very close to that of 16mm, in fact it is so close that the British company Walton Films, in the 1960s used to make colour 9.5mm prints by re-perforating 16mm ones, and slitting off the edges, you can always recognise these prints, as there is a very narrow frame bar, cut into by the perforation, and the picture runs right to the edge of the film, in fact, it has been cropped slightly. Centre perforation does give a greater percentage of film area used by the picture frame, but there is a price to pay. Formats which run the picture very close to the edge of the flm, 9.5, standard 8 and super 16 being the best known, are prone to scratching at the edge of the image, the film has to contact sprockets, rollers, pressure plates etc. somewhere, and nice wide edge margins, as on 35mm, are very useful for this purpose.

Pathe also had another format which attempted to maximise the frame size, in a different way. This was the 17.5mm Pathe 'Rural', which was similar to 16mm, perforations on one edge, optical track on the other, it actually had the perfs on the right, and the track on the left, like the old DIN 16mm standard. This format was intended for showing reduction prints of normal 35mm films in small communities which did not have a permanent cinema, hence the name. It had frames with rounded corners, of fairly large radius, and small, almost square perforations were tucked into the space thus made available. This format was supressed by the Nazis during the war, and did not re-appear afterwards. Both machines and prints are now quite rare.

You propose a frame with of 7.6mm, I feel that this is far more than could be achieved in practice. If magnetic sound is to be used, then a stripe of about 1mm will be needed, it is desirable to also include a balance stripe, an two stripes, or one wider one, will be needed for stereo sound, so about 2mm is needed for the tracks. Allowing the minimum of margins on the film would give a maximum frame width of about 5.5mm.

Another problem which 9.5mm has is that any perforation damage, and film scratching by the claw is visable in the picture area, Many 9.5mm projectors were of very poor quality, and severe centre scratching is very common on old 9.5mm prints.

In practice, the disadvantages of centre perforation tend to outweigh the advantages. I know of over a hundred film formats, and I am sure there are many others, I only know of about half a dozen where the perfs are between the frames, either in the centre, or towards the edges.