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This topic comprises 5 pages: 1 2 3 4 5
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Topic: Film is nitrate... now what?
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Bernard Tonks
Jedi Master Film Handler
Posts: 619
From: Cranleigh, Surrey, England
Registered: Apr 2001
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posted 07-21-2006 03:23 PM
quote: Brad Miller
Of course that would require getting Kinoton to do it. ![[Wink]](wink.gif)
Kinoton could copy the old British B-T-H projectors that had cutters incorporated in the fire traps of both spool boxes. The fuse was a frame of nitrate film above the gate, which also released the contactors for projector motor and arc lamp. You were also unable to open the spool boxes during projection.
The putrid smell of nitrate stock could not be mistaken, and the memory has remained with me, also the reels were heavier in weight than safety film.
During the early part of the 1950’s many re-issue nitrate prints that were clean treated had an extremely strong smell of vinegar. These nearly knocked you out when you opened the can and during projection, some copies also buckled very badly. Another cleaning process was as strong but had a more pleasant smell like acetone, also the base side was turned to a matte surface.
Until at least 1953 when nitrate stock was being used up on newsreels, we used to share the news with another cinema. Travel was on the trolley buses with the unspooled film of fewer than 1,000 feet in the metal can for lightness, when we should have been made to carry the film in the transit case as well for safety.
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Stephen Furley
Film God
Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002
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posted 07-21-2006 06:15 PM
quote: John Pytlak
silver nitrate is one of the chemicals used in making emulsion (silver nitrate + halide salts forms the light-sensitive silver halide crystals in film)
There actually are people who make their own photographic emulsion, and coat their own film! After Kodak discontinued dye-transfer matrix film (sheets for still photography, not Technicolor motion picture stuff) there were people who made their own.
There's also been considrable renewed interest in recent years in the so-called 'alternative processes' of photography. Many of these require chemicals which are either exotic, and difficult to obtain, or highly toxic, such as mercury fumes, or cyanide.
However, there is an alternative printing process which is easy to do at home, does not require a photographic darkroom, and is not terribly toxic, though sensible precautions should be taken with silver nitrate, e.g. don't lick you fingers, wash hands afterwards etc.
This is the 'salt print' process. This is a contact printing process, so a larger negative is desirable, though you can do it with 35mm.
You need a good quality white paper, photocopy paper is rather too thin, and it needs to be uncoated, art shops sell suitable paper.
Make up a strong solution of sodium chloride (common salt), this can be made up with tap water.
Soak the paper in this solution, and lay it out to dry. It is not light sensitive at this stage.
Make up a solution of silver nitrate, this does need to be made up with distilled water; the chlorine in tap water would cause problems.
Brush the silver nitrate solution onto the paper; this sensitises it by forming silver chloride. Sodium nitrate is also formed, but plays no part in the process.
Put the paper away in a reasonably dark place to dry.
Place the negative emulsion down on top of the paper, and hold them in contact with a sheet of glass. Various objects, leaves etc. can be used instead of a negative.
Expose to strong light, srong direct sunlight will need about five minutes exposure, other sources rather longer. Putting it inside a carbon arc lamphouse also works, but this isn't really practical with xenon, so sunlight is probably the best illumination to use.
The exposed paper will turn brown, forming a positive image. The problem is that the print would have to be kept in the dark, or the whole sheet would darken, the unexposed silver chloride is still light sensitive. The print can be fixed by washing out the unused silver chloride, together with the sodium nitrate and any remaining sodium chloride, which would attack the image, with luke warm water. The image is rather delicate, so running water should not be used, but rather several changes of water in a dish. When the wash water no longer turns cloudy the washing is complete, and the print can be tried.
Anybody want to try it, and post the results?
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Stephen Furley
Film God
Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002
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posted 07-22-2006 08:16 AM
No, but it should be somewhat simpler to make than Ektachrome, or similar, films.
Details of the process have been published, both the current (K14?) and the previous (K12?) versions, so in theory you could make up your own chemistry, and do the processing. I believe that some of the raw cemicals are not commercially manufactured, so you might need to find a way to make those as well. I wouldn't put it beyond somebody to try!
At one of the Momi Wednesday evening lectures many years ago Brian Coe said that he had hand-processed Kodachrome in sheet form, but I wouldn't want to try it. I remember doing C22 and E2/E3, and they were bad enough. The only advantage they had over C41 and E6 was that they were done at lower temperatures. They involved far more baths and a much longer processing cycle though.
I think Kodak are trying to stop me using any of their products; all of the ones which I use are the ones which get dropped. ![[Frown]](frown.gif) Royal Gold 25, Panatomic-X , Technical Pan, Kodachrome 25, Black and white papers etc.
Dye transfer printing is not easy; to make your own materials as well really is dedication to a processes. People are even making Daguerreotypes again, not to mention the most incredible revival of all, Lippmann photographs are being made by a handful of people. I've only ever seen one of those, and the plate had been badly water damaged at some time; only a small part of the image had survived. Somebody managed to do away with the leather bag filled with mercury, and simply use the optical discontinuity between the emusion and the air as the reflector. I won't describe the process; nobody would believe me that it existed, or that it worked, but it did. There are websites which describe the process, and it occasionally gets discussed on photographic newsgroups. It had certain things in common with Holography, and I believe that some of the people that have revived the process work in that field, and therefore have access to useful materials and experience.
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Frank Angel
Film God
Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999
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posted 07-15-2007 05:01 AM
Yah, nitrate film might be more dangerous to handle than safety film, but remember it was used on a daily basis for decades, in every theatre in the country for nearly a half a century. And people didn't run screaming in fear from it; they just knew the dangers and were well versed in how to take the necessary precautions. I know is sounds like nitroglyceren but it's not. It's move film and it runs perfectly well in projectors designed to handle it.
The one thing that I would add in nitrate film's defense, is that a nitrate print produced a projected image unlike anything I have ever seen from safety film. I ran quite a number of WB cartoons in the late 60s that evidently were overlooked in the depot which serviced our theatre in Byran-College Station TX. We ran plenty of B&W short subjects that also came in on nitrate. I remember to this day how those images had this quality....difficult to put into words -- I think the best way to describe it is "shimmering" or "effervescent" and three dimentional -- maybe the silver in B&W films gave them that mercurial quality. And it sure was a dazzeling and unmistakable quality. Add with the Technicolor process as in the cartoons... that was downright spectacular. This exceptional quality that the nitrate film was able to produce, very different than acetate or poly, is too often overlooked, IMHO. Rushing off to copy them to other media, even today's best modern stocks, let alone video which can't come close to reproducing those amazing subtilties, is short-sighted. There's something to be said for keeping and storing any nitrate prints that are still in good condition for as long as possible. Copy them, sure; but we shouldn't be so fast to then destroy the nitrate.
I would imagine quite a number of booths could still be easily recertified for nitrate. All I would need in ours would be to get rid of the DTS reader and we'd be in business -- all the fire traps are in place and I've never retired the 6000ft magazine, only because they look so cool compared to those naked looking reel arms. We still have fire shutters on all the port windows with the fusable links are still in tact; any one of them goes off and even the fireproof booth doors will slam shut, turning the operator into a very tasty projectionst flambé.
I'd love to run some nitrate just so an audience and film students could see what that unique process actually looked like.
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Stephen Furley
Film God
Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002
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posted 07-15-2007 06:20 AM
quote:
I would imagine quite a number of booths could still be easily recertified for nitrate. All I would need in ours would be to get rid of the DTS reader and we'd be in business -- all the fire traps are in place and I've never retired the 6000ft magazine, only because they look so cool compared to those naked looking reel arms. We still have fire shutters on all the port windows with the fusable links are still in tact; any one of them goes off and even the fireproof booth doors will slam shut, turning the operator into a very tasty projectionst flambé.
Were you allowed 6000 foot magazines with nitrate over there? Here they were not permitted; it wasn't just a question of how much film was actually on the machine; the had to be constructed so that it was impossible for them to contain more than the permitted amount. Large spools came in for 3-D prints, which were made on safety stock. As luck would have it, nitrate finished at just about the time that 3-D started.
AT the NFT in London they use Cinemeccanica Victoria 8 projectors, which were fitted with 70mm 6000 foot spool boxes. When running nitrate they actually had 2000 foot 35mm spoolboxes, which fitted inside these. The doors of the main spoolboxes have been removed sometime in the last ten years or so, but the small boxes which fit inside them are still used. If you can get hold of the BKSTS 'Cinema Technology' magazine for March 2007 there are some pictures of the setup on page 45.
To return to a point that I made in another thread, even if you still have all the precautions in place which were required when you last ran nitrate in the past, I think you would find it very difficult to get a licence to do so today. People today are just to scared of nitrate to risk issuing a licence to project it. They have nothing to lose by not allowing it, and nothing to gain by doing so. If there was a serious accident involving nitrate, then they would almost certainly receive some of the blame, since they permitted its use.
There's an interesting experiment that I've tried a few times; take a small roll of nitrate film, maybe 100-200 feet, and hand it to somebody, without telling them what it is. Let them handle it, unroll a few feet of it, look at it, etc. No problems. Then tell them that it's nitrate, and see how they react. In most cases they are quite alarmed at what they have been handling, then they think about it, and realise that their initial reaction was quite out of proportion to the risk. The same people handle hazardous substances every day, the fill their cars with petrol, one of them previously worked at John Myland, Web page , where he used to handle large drums of volatile, flammable solvents, another was retired, but had worked at the plant that re-processes spent nuclear fuel rods, clearly both hazardous materials, and yet they perceived a greater risk from simply holding a small roll of nitrate film. Most people these days are not familiar with nitrate film; I would guess that even in this group, where almost all of us handle film prints, at least 80% have probably never seen, or handled, a reel of nitrate.
Ultimately whether you can run nitrate depends on whether you can get somebody to sign the bit of paper allowing you to do so, and I think that would be the problem. Even where there are laws totally prohibiting the screening of nitrate prints, this need not, in theory, be a problem; laws can be changed, but getting people to change them, or to issue licences, would be very difficult today I think.
I still think that everybody who handles 35mm film prints in cinemas should be required to have some basic training in nitrate, which should involve actually handling a reel of the stuff, unless they are working under the supervision of somebody who has received such training. At least then they would stand a reasonable chance of recognising what it is in the unlikely event that a nitrate print should ever turn up.
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