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                                                                Film Dimensions

I must start with an apology. Many of the images in here, I came to realise as I went thru them, were accumulated in days long before I had any thought of a website. At that time I was just copying stuff of interest to me, and seem to have failed to always record and show where information came from. If anyone has an issue, please contact me and I will add a credit or remove the offending item.

I have been reviewing this page to renew the pictures and trying to introduce a bit more logic than there was in the past. It's tricky to know how to break the subject into manageable chunks without missing bits. However, let me start with a brief historical survey. It all started of course with 35mm and even the Americans were forced to use 'mm' instead of 'in' sometimes. Not only did 35mm rapidly become established as the de facto standard but a vitally important part of the process was SMPE (as it then was) standards for a variety of technical aspects and dimensions. The final leg of this tripod was the establishment by Bell and Howell of machines of a very high standard of accuracy for perforating and other processes. Although many other formats were tried, 35mm remained the near-universal standard for cinema until film was replaced by digital. The so-called "sub-standard" or, as I prefer, narrow-gauge formats were all influenced, if only obliquely, by the 35mm standard.

The most directly-derived format was of course 17.5mm. There were various attempts at a 17.5 format but only one, the Pathé Rural, was ever used commercially on any scale (I except the 17.5 size, more properly regarded as half 35 than a format in its own right,  that was used in some back-room processes in the industry). The other most directly-derived format was of course 9.5mm, again from Pathé. Something I regard as important about both 17.5 and 9.5 is the fact that they both lacked the degree of consistency, quality and repeatability conferred by the standards I have mentioned above that ruled 35mm, not least because they were principally Pathé gauges and relatively little adopted by other major concerns. Even Pathé's own 28mm had been standardised through American efforts, annd 16mm too had an SMPE standard, which in turn largely passed through to Standard 8mm. Super 8 was in a way sui generis as it was, uniquely, a deliberate development beyond an existing narrow-gauge format (Standard 8 I exclude because it just used the old sprocket holes of 16mm, ludicrous though this was in terms of picture size). However, Super 8 was, I believe, deliberately designed for general adoption and was correpondingly highly standardised, even if not by the SMPTE. I have, incidentally, never really swallowed the story that 16mm derived just from an objective consideration of all the technical factors. I am sure Kodak was aware of what Pathé was up to but didn't like centre sprockets. Bell and Howell had done the more logical thing and developed a 17.5mm prototype, but were trumped by Kodak's oven-ready 16mm. A pity; Kodak's choice and the marketing muscle behind it made 16mm the de facto standard for semi-professional use, despite 17.5mm being so much more logical. VHS and Betamax re-played.

I'm not going to make any more general comments as I'm sure many will disagree with some of the foregoing. In conformity with the main gauge-based structure of the site, I shall see if it works dividing things up by gauges, starting with my first love, 9.5mm.

Because of the rather proprietary nature of 9.5 there is little formally-published information. I have, however, come into possession of some Pathé technical drawings about Duplex (thanks mostly to Ken Valentine) and have spent some time processing them into a presentable form. But first, Pathescope's description of the 9.5 process as published in Pathescope Monthly.

 

I have taken the unusual step of reproducing these pix in full size rather than as the usual expanding miniatures because they are so basic to 9.5. The third is just an enlargement of part of the second. This stuff I shall leave largely to explain itself, but I would just add that these images help show where problems of lack of standards and quality control familiar to 9.5ers can arise. First, note that the printing and development is all done before perforation. This is sensible to minimise the interfeence of sprocket holes with circulation of development chemicals, but it can and often does result in differences in precisely where the sprocket hole appears in relation to the picture. Hence the need for some form of framing device or racking, although this was far from normal on Pathé projectors. The second issue is similar in principle but applicable only to notched films. As can just be perceived in the enlargement, the edges of two of the prints are very slightly notched in a squared cut-out opposite the main notch. The displacement of the notch even slightly can produce this second notch, familiar as a sharp uneven edge to many a 9.5er. I am indebted to Patrick Moules for this explanation of something that had long puzzled me. I shall look for the third print in future.

I shall also produce this next image  (from P. Moules) in a large format; it shows how complex the whole process could get, with all manner of different dimensions arising from a variety of factors. I spent a lot of time on this one, which has appeared in 9.5 magazine.

 

This, incidentally, is what I started with.

 

In the sound era, too, Pathé/Pathescope failed to control quality to high enough standards. I don't recall Pathescope doing anything quite as crass as printing the sound track in negative, as Pathé France did at first, but there was a fair bit of picture weave in films like Glass Mountain. It was obviously expected from the start that sound tracks would wander, as witness the sound reader on the Vox and I have encountered the same phenomenon on 17.5. Limited as the availability of documents in the UK and in English is, I can offer only two images of sound film "standards" for 9.5.

     

Pathescope with typical modesty described 9.5 sound as "the greatest achievement in the history of cinematography". If only they had rigorously pursued these standards. (Both images are I think from Pathescope Monthly.) Some films were issued with re-recorded sound, but by no means all, as witness Edge of the World for example.

Then there was Duplex, about which I shall not comment, beyond saying that it seems to be commonly viewed as one of the last nails in Pathescope's coffin.

                         

The last image is from a Pathescope catlog.

Now another thing about 9.5 sound. Here is a note I put together from responses by Graham Newnham to a magnetic sound query I raised with him, in about 2006. Just a small sample of the sort of knowledge we lose with people like Grahame.

9.5 mag std

 

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 A new page for the remaining gauges.

16mm

I have very little on 16mm, I suppose because it has never been of much interest to me. Most of the titles on 16 seemed to me to be incomprehensible, in terms of where anyone got the idea, how on earth they sold it to a film producer, why it was made, put onto 16mm and then ultimately sold to who? Is there really anyone who would want to view some of this dross once, let alone own for presumably their repeated delight? There are also far too many dupes and prices far too high for any film worth owning. But who am I to talk - I'm big into 9.5 and 17.5!

     

Pic 1 is actually from a Debrie Handbook. 

That's about it, really. There were a few early attempts at a different format, quite apart from the much later Super 16. Here is some info. 

                

I include Ozophane here because I met it on 16mm, one of the many and varied attractions of the old Buckingham Film Museum. It was on a very thin base which did not appear to be terribly strong; the projector I saw used a velvet-lined gate, which made me think the film must have been fragile.

This may be the time to look at the so-called "Gauge Wars", when comparisons were frequently made between the three amateur formats then extant. Apart from cost and things like the range and capabilities of available equipment, film size itself was the focus of considerable attention. Pathescope in particular used to bang on quite a bit about how efficient 9.5mm was in terms of the percentage of the total film area used for the image. No mention was made, of course, of the percentage of image area likely to be marred by scratching. Such comparisons were inevitably more muted in the sound era when 9.5 had lost a chunk of its picture area to a sound track.

               

8mm

 Some of the territory is covered in the gauge comparisons above. Pic 1 reveals that the Standard 8mm image was 4.37mm by 3.28mm and covered less than half of the surface area. I have seen professional material on 8mm and some excellent amateur footage, but while these show what the gauge could achieve, size was limited if a decent screen image was to be obtained. Pic 1 also shows that the film image had to be magnified 228 times to get a one metre picture. Interestingly, Super 8 was not actually that much better. However, my copy of The Lion King exhibits amazing quality. 

In November 1965, not long after the introduction of Super 8, ACW did a detailed comparison of the two 8mm formats.

          
I have also included a snippet about an aborted optical sound proposal for Standard 8. There was an 8mm projector with provision for optical tacks, The Toei Talkie, but nothing ever came of it. I would love to know more if anyone has any information or even some film. The final pic is from SmallFormat magazine, showing the highly logical 8.75mm film from China because 8.75 is precisely 25% of 35. Maximum economy!

17.5

As I mentioned above, 17.5 never had a formal, published standard, and it was years before I came across a decent image, for which I am indebted to J C Laubie. I find it hard to understand why Kodak came up with 16mm when 17.5 does seem, objectively, to have the edge, although admittedly 17.5 would have been more costly as it had a much longer pitch, 9.5mm as against 7.62mm for 16mm.

               

It is well known that 17.5 was , for logical reasons, chosen by many pioneers to try out (pic 2), and one rather later (pic 3). I have included an image I put together directly comparing 16mm and 17.5mm.

28mm (and 22mm)

28mm was the first commercially-successful attempt at a gauge smaller than 35mm. Although sometimes regarded as a curiosity, 28mm did much to pave the way for the smaller gauges that became possible as film technology advanced and better quality could be gotten from smaller images. Edison's 22mm, introduced in the same year, rapidly became a white elephant, not only because of the very small image size but because the technology was wrong - repeated forward and reverse cranking just didn't meet the need.

28mm, as already mentioned, did have its own standard thru the SMPE.

          

At one point, there were three Edison 22mmm Home Kinetoscopes on American eBay, so I grabbed lots of pix; they're on a page linked to this one. Individual pictures were 4mm x 6mm.

35mm and beyond

This is just a collection of bits and pieces that I came across at one time or another.

                              
         DOLBYEVOLUTION.pdf
For 35mm and larger, you could do a lot worse than the BKSTS wallcharts put together by Grant Lobban, which show all sorts of details about 35mm (and bigger) including colour processes, sound and etc. This eems to be a sensible place to put in this pdf on the development of Dolby sound.

 

Finally, a table I put together with info from the various sources listed here. It is by no means complete and there are some inconsistences, so any help filling it in would be welcome. 

 

Here are a couple of links if you want to look at gauges in more detail - there have been far more than I have listed on this site, tho 3.2mm does have a page.

Wikipedia has an exhaustive list - http://en.wikipedia.org/wiki/List_of_film_formats. See also:-

http://oldfilm.org/content/brief-history-amateur-film-gauges-and-related-equipment-1899-2001

 

 

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LOOKING AFTER

And Restoring Films and Projectors

An awful lot of what I do comes into this category, whether it be films, projectors or, indeed, documentation

Here are the main sections:-

1. Restoration, with some thoughts on what is and is not acceptable

2. Back From The Bodge - an example of restoration after severe bodgery

3. Care and Repair of films. This comes in a very basic first chapter for beginners, and then some slightly more advanced stuff, plus a section on Cleaning and Preservation topics, with a sub-page on Camphor.

4. Old Projector Amplifiers. Some hints on how to avoid doing more harm than good.

5. "Detailing" a projector(cleaning and smartening up for display)

Other articles in a similar vein can be found under the various gauges, eg Reviving a KOK in 28mm and Reviving a 200B in 9.5 Silent.

Although I have given up on 16mm features, I seem to have a number of silents and shorts in need of repair. I have therefore modified my 16mm splicer to help. First, I removed the blade as I find it is all too easy to cut the film as well, and now just use a craft knife or single-sided razor-like thing. In order to help with sprocket repair, I have added the extra spools of pre-perforated tape. These are on a cantilever so I can still get the film to the splicer. I won't know until I've used it a bit whether it would be better to have the cantilever the other way round. The support is, of course, made of Meccano (TM)  - why make if you have the wherewithal to hand? The tape spools are deliberately left very free, so either can be brought into position. My final mod is hard to see, so I have marked the ends in red. Basically, it is a strip of metal about 3mm from the front edge of the film bed. I pull tape out with a very small-bladed screwdriver and lay it across the sprockets on the front edge. The metal strip then provides an edge against which I can cut the tape at a convenient size to give a wrap-round. This sort of repair is useful because it does not encroach on the picture area, and I use it on most gauges.

Leafing idly thru some late 40's ACW's. I came across one comment that made me stop and think. The context was a discussion of the merits of centre versus edge perforations. The comment referred to the way a film gate is "relieved" around the picture area, ie cut back slightly so that, while the edges of the film are gripped to ensure the image is held steadily in the gate, the picture area should not be in contact with any part of the gate except at the aperture, so minimising the risk of scratching. The point was made that, for 9.5 with its central perfs, the film was not directly supported where the claw enters the perf to do its work. In 16 and 8, the sprocket hole is very closely supported by the side runners of the gate.

The suggestion was made that this meant the 9.5 sprocket was more prone to damage and, on reflection, I think there could be something in it. If one imagines gripping a piece of film in a vice, with just an eighth or less of an inch protruding, it will seem very stiff to the touch, and strong enough to cut an incautious finger, A few inches of film would just flop around loose. It would seem logical that, albeit on a very much smaller scale, a similar effect could operate in a projector. There is certainly scope for the film to move in and out fractionally as the claw enters and leaves, which may contribute to splitting. I have often seen 9.5 projectors in which wear to the claw has resulted in the underside becoming notched, so that it may actually catch on the bottom of the perf on the out stroke. It would seem possible that the lack of support around the perf could be a contributory factor in any damage. It's interesting as much as anything because I would like to think that there is some reason for the appalling, incessant sprocket damage one sees in so many 9.5 prints other than the sheer incompetence of projectionists.

 

 

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PPT

 

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PROJECTED PICTURE TRUST

 

 

 

Some years ago, before work and then illness intervened, I was actively involved with the Projected Picture Trust (PPT) For those who may not know,

this is a charitable trust dedicated to preserving the equipment that was used to show films in the commercial cinema, but also home movie machines.

For all the organisations/bodies/coverage involved with film, the PPT is virtually the only one that focuses on the machines. The Science Museum/Bradford don't seem

very interested and without the PPT little would survive. Even so, it's a constant battle against against time and very limited resources.

 

The PPT has a small cinema at Bletchley Park with a display of machines. Here are some pictures that Mikael Barnard took for me to give some idea of

what the PPT does, focussing mostly on my main interest of narrow gauge.

 

 

 

 

The PPT has its own website at http://www.ppttrust.org/ and has prepared a CD ROM showing many of the machines they have collected.

 

 

 

 

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