Film-Tech Forum ARCHIVE: K19 on silver nitrate?

This is topic K19 on silver nitrate? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Mike Jones (Member # 522) on 07-16-2002, 12:20 PM:

i hear we're getting a print of K19 on silver nitrate film stock. anybody know anything about this? regardless, its cooler than your mom.

Posted by Paul G. Thompson (Member # 655) on 07-16-2002, 01:00 PM:

If you are referring to nitrate stock, I don't think that will happen.

Posted by Leo Enticknap (Member # 534) on 07-16-2002, 02:10 PM:

I haven't heard of K19. Searching under that on IMDB came up with 119 (1984) and K-9 (1989).

If this film exists and was produced in the US after February 1950 (when Eastman Kodak discontinued nitrate print stock), no nitrate prints will have been made.

Posted by David Stambaugh (Member # 1102) on 07-16-2002, 02:32 PM:

It's the new Harrison Ford movie opening this weekend.
K-19: The Widowmaker

Posted by Stephen Furley (Member # 1277) on 07-16-2002, 04:45 PM:

Silver nitrate is used in making photographic emulsions, it is used to form the silver halide, mainly bromide, but sometimes also containing chloride or iodide. It is normally obtained as white crystals, which can be disolved in distilled water to give a clear solution. Both crystals and solution will produce brown stains on skin, which are difficult to remove.

Since silver nitrate is used in making just about all film stock, except spacing and mag recording stock, but almost none should remain in the finished emulsion, the term 'silver nitrate film stock' doesn't really make any sense. Where did you hear/read this? The only thing I can think of would be either a print on black and white stock, or a colour print using one of the processes where not all of the silver is removed in the bleaching stage. The silver in these prints would have been produced indirectly from silver nitrate, but it still doesn't seem to be a very meaningful name.

For anybody who wants to play with silver nitrate, it is easy to make salt prints, similar to those made by Fox Talbot. Make a solution on sodium chloride, common salt, soak white writing paper in it, and dry. In subdued light, brush on a solution of silver nitrate, and dry again in the dark. Do not put the brush back in the nitrate solution after it has touched the paper, as it will contaminate the solution, forming a white precipitate. This precipitate is what you want to form on the paper, but not in the bottle, it is silver chloride. When the paper is dry, expose it in a printing frame, or under a sheet of glass, through a negative, or various objects, leaves, lace etc. several minutes exposure to a source rich in ultra violet will turn the exposed areas brown, I use either sunlight, or the inside of a carbon arc lamphouse. The print can be fixed by washing in several changes of slightly warm water, untill there is no cloudyness in the water. You should now have a salt print - and brown stains on your fingers for the next week or so!

Silver nitrate is toxic, and obviously excessive exposure to ultra violet radiation is something to avoid, but with reasonable care, the process is pretty safe.

Posted by Brad Miller (Member # 2) on 07-16-2002, 05:00 PM:

The print is probably that silver retention process that bleaches colors, like Sleepy Hollow had. I haven't had my hands on a print, so I can't say this for sure yet.

Posted by Steve Kraus (Member # 476) on 07-16-2002, 05:08 PM:

It had that look so in all likelyhood that's what the O.P. heard.

Note that this sort of processing is controllable as to degree as the bleaching step that removes the silver can be eliminated or reduced in varying degrees.

Posted by Frank Angel (Member # 248) on 07-17-2002, 12:18 AM:

And the purpose of leaving some silver in the print is to produce a certain look? Deeper blacks or something?

Posted by Les Brock (Member # 1041) on 07-17-2002, 02:24 AM:

Silver enhancement is used to give deeper blacks and higher contrast.

I am sure when John Pytlak sees this subject he will direct you to the Kodak knowledge database link on the subject.

Posted by Les Brock (Member # 1041) on 07-17-2002, 05:27 AM:

In film labs the process is called ENR.

Further info at
www.kodak.com/country/us/en/motion/support/processing/skip.shtml

Posted by John Pytlak (Member # 331) on 07-17-2002, 11:26 AM:

Here are some additional links:
http://cameraguild.com/technology/testing_limits.htm
http://www.cinematographer.com/article/mainv/0,7220,34805,00.html

The second link is to an excellent article about special process techniques in American Cinematographer called "Soup du Jour". Unfortunately, it may not be accessable as Creative Planet / American Cinematographer upgrade their websites.

Recall that the prints of "Minority Report" used both silver retention and Kodak VISION Premier Color Print Film 2393 to achieve their unique look and very rich black level.

Here are some additional Kodak articles:
http://www.kodak.com/country/US/en/motion/support/processing/skip.shtml
http://www.kodak.com/country/US/en/motion/newsletters/inCamera/july2000/dark.shtml
http://www.kodak.com/country/US/en/motion/newsletters/inCamera/april2002/ktP.shtml
http://www.kodak.com/country/US/en/motion/newsletters/inCamera/fall98/preview.shtml
http://www.kodak.com/country/US/en/motion/newsletters/inCamera/oct2000/jubaku.shtml

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by John Hawkinson (Member # 1135) on 07-17-2002, 02:48 PM:

I believe that "ENR" is Technicolor's proprietary bleach-bypass process (named after Ernesto Novelli-Raimond), and that the term "ENR" shouldn't be used to refer to other labs' bleach-bypass.

--jhawk

Posted by John Pytlak (Member # 331) on 07-17-2002, 02:58 PM:

"ENR" is Technicolor's tradename for their proprietary silver-retention process, which can control the amount of silver left in the film.
http://www.theasc.com/magazine/nov98/soupdujour/pg1.htm (ASC "Soup du Jour" article)
http://www.theasc.com/magazine/feb01/storaro/pg1.htm
http://www.cameraguild.com/interviews/chat_storaro/storaro_bulworth.htm

Posted by Mike Jones (Member # 522) on 07-18-2002, 02:01 PM:

I was told second hand that our booker said we were getting "silver nitrate" blah blah. so, thanks to everyone for their input.

mike

Posted by Gordon McLeod (Member # 33) on 07-19-2002, 09:40 AM:

Remember that retained silver prints will absorb more heat than from the lamp than regular dye prints so as such it is import to prevent blistering to have the lamp system properly focused and cooled

Posted by Frank Angel (Member # 248) on 07-20-2002, 02:41 PM:

OK, Gordon, I know this is going to take a left turn off topic here, but since you brought it up, let me put this to you: I am having trouble with one of the ORCON lamphouses in that no matter how well I seem to align and focus it, I can't get rid of a very distinct hot spot. I used the mechanical distance setting tool -- the one that sits in lens holder and passes the rod thru to the gate and sits on the bulb holder. The distance seems fine but the rod does seem like it has a slight angle to it. Problem is, this ORCON lamphouse and the Xetrons that I use at in the small theatre, they all sit on the pedestal base with the mounting holes all matching. However, the base has no adjustments whatsoever in the platform that the lamphouse is mounted on. There is no way to adjust the physical height or left/right orientation in relationship to the projector head. The lamphouses sit in a groove in the pedestal and the only thing you can do is make a gross distance adjustment toward or back from the head by way of the slots in the platform that holds the lamphouse locking screws. Even that is a bit silly because the mating cone of the lamphouse and the docking cone of the Century head don't have much leeway -- if you were to back the lamphouse off, even an inch or two, you would have this big gap spilling light between the lamphouse and the projector. So even though the lamphouse looks like you can set it at any distance you want (the screw slots are about six inches in length), only a single position will actually mate with the projector correctly and prevent light spill from the lamphouse.

This leaves only the three allen adjustments on the lamphouse -- the left and right mirror adjustments and the focusing adjustment. So far, no manner of adjusting these will eliminate that hot spot. And believe me, I have spent hours trying. I've followed the book about centering the round shadow so that no hot spot "peeks" out around it, but then when the lens is in, it is obvious that there is a hot-spot and the adjustments will move it side ways, up and down, but not eliminate it. The focus adjust will reduce it, but also that reduces the overall brightness. The second machine seems to give me very good brightness and almost no hot spot, but even this is not as even a light as I am used to getting from the old Peerless Magnarc.

So this is what I don't understand -- since the alignment of the lamphouse to the projector head is supposed to be so critical, how is it that there are no physical adjustments other than distance of the lamphouse to the projector head? The lamphouse and projector are sitting on a standard Simplex pedestal. It seems that the lamphouse platform is aligned to the projector head because when the lamphouse sits in the platform grooves, the two cones do meet perfectly.

I am assuming that xenon alignment is even more critical than carbon arc because with the Peerless, you just got the physical distance between the projector aperture and the lamphouse arc to 18in and that was all the physical adjustment you needed to do in the placement of the lamphouse on the pedestal -- any vertical or horizontal alignment was done by the fact that the lamphouse could only be screwed into one place on the pedestal platform -- same as with the ORCON and Xetrons. Once the Peerless lamphouse is sitting on the platform correctly you could get perfect end-to-end brightness simply by the mirror adjustments and the focus adjustment on the lamphouse.

So what other kind of adjustment can be made to this xenon lamphouse that will rid me of the hot spot? Is the pedestal not the correct base for this lamphouse? Should it have the ability to physically move the lamphouse in relation to the head -- up and down, left and right? Funny thing is, with a picture on the screen, the hot-spot was hardly visible. Yet, I want to get a much more even illumination than I am getting, especially since the second machine is putting out very good light with hardly any hot-spot.

Any help will be appreciated. If I am missing something very obvious, please be gentle.

Frank

Posted by Gordon McLeod (Member # 33) on 07-20-2002, 04:55 PM:

Actually carbon arc alignment is also criticle and there were rod alignment kits and string kits for most. But the large plasma ball in the crater was more forgiving
Most bases have adjustment, the simplex is the least (except for the 3 and five point bases) but there is some left right adjustment and verticle adjustment
On one version it entails a excentric locking bolts
As for between the nose cone and the head just put a piece of stove pipe to fill in the gab if required