8mm Forum: Of Film layers and incorrect theories on fading?

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Posted by Osi Osgood (Member # 424) on May 17, 2014, 01:19 PM:

I have a question that has bothered me for awhile, and, happily admitting that I don't know everything about super 8 optical sound (and this would apply to ANY optical sound film, 16MM
ect)

... I have heard that when they produced super 8 optical sound, they actually did two "passes" on the film.

1. To print the image on the film.
2. To place on the optical track.

Now, I have noticed on the few prints that I have, that have color fade, most of them have a perfectly black optical track, while the image is faded.

I have also heard that a "fixative" of some form is used to make sure that the optical track does not fade, which seems to have worked brilliantly.

I have also noted that as the very edge of the image (next to the optical track), there is the slightest bit of the image that has absolutely perfect color, which I believe is because the fixative used for the optical track comes over slightly onto the very edge of the image.

So, my questions are two fold ...

1. Could the image, that has faded, be due NOT to film layers fading, but instead, of the final fixative place on the top of the image.

2. If so ... (referring to question 1#), could that faulty fixative be ...

a. Replaced
b. be somehow renewed, thereby returning the original color to the printed film, which may still exist under that fixative layer?

In other words, could much of the fading on faded print, not be due to a specific color layer, or any layer but instead, to a bad "protective/fixative" layer on the top?

This is a curiosity that has been perked by none other than my "Grizzly Adams" print that, while the image is faded, the optical track is pristine and, there is the slightest bit on the edge of the frame/image, where the color is absolutely perfect. This is in fact, the sole reason WHY this question has come up.

If the color on the very edge of the frame is spot on, and the rest, faded, is this because of, not layers fading, but the fixative/protective used to finish the print?

I thank you for your time and the expected info!

Posted by Maurizio Di Cintio (Member # 144) on May 18, 2014, 03:53 AM:

Or perhaps there is no fixative on the film other than on the optical soundtrack area: this would account for the tiny fraction of image being perfect in color right on the edge next to the soundtrack IMHO. Fact is this is the first time I heard about such fixative... Surely the more experienced forum memebers can clarify...

Posted by Larry Arpin (Member # 744) on May 18, 2014, 10:23 AM:

I had a faded print with a tape splice and the part where the tape was had good color. But it too eventually faded. All film goes through a fix bath as part of the developing process. Optical soundtracks are applicated to give better sound. Not sure what the liquid is but without it the sound would not be good.

Posted by Allan Broadfield (Member # 2298) on May 18, 2014, 05:03 PM:

Back in the days of silver optical tracks, after the image on the film had been fixed the optical sound section was re-developed by laying on it a thick bead of applicator fluid which re-developed it bringing it back to a silver image, which was needed to give it contrast and maximum frequency response. This is possibly the reason that any other image caught in that section has retained it's colour.

Posted by Osi Osgood (Member # 424) on May 19, 2014, 12:56 PM:

Hmmmm ...

Now we might be getting somewhere!

If I can discover what the exact fixative was , perhaps, with some unwanted optical super 8 ashort I have, try an experiment to run it through, as the correct amount of time through a fixative, and see what happens, as I have always found it rather odd that usually the cyan level disappears rather quickly.

Perhaps that "reddish" hue to those ole films can be due to a fixative, the fixative itself being the "reddish" culprit and not the film stock itself ...

however, even that "theory itself I have to call into question as, when old Eastman film stock reaches it's total and complete death (from what I understand, as I have never actually witnessed it), EVERYTHING is reddish and if left for a long enough time, the film would actually turn white? (I mean, no image left period))

Posted by David M. Ballew (Member # 1818) on May 19, 2014, 03:15 PM:

Osi,

The question you raise brings to mind a common phenomenon in the world of 35mm projection that I think might provide a clue for part of the answer.

Sometimes one finds old policy or intermission loops that were projected at theatres for years on end, especially drive-ins. There will be catastrophic picture fade within a 1.85:1 area in the dead center of the full Academy frame, but absolutely vivid color and detail outside of that area. The area exposed to full-on lamphouse light through the widescreen aperture gets “bleached out,” as it were, but the portion of the frame shielded from light by the aperture plate remains nearly pristine. This is especially prevalent with ordinary photochemical prints, which are obviously light sensitive, but even sometimes happens with IB Technicolor. Even a medium as robust as IB Tech will apparently break down if you repeatedly zap it with bright enough light.

What I wonder is whether the sliver of pristine color on your prints is owing to the slightly reduced size of a Super 8 projector gate as opposed to a camera or printer gate. In my theory, the reason that sliver of picture and the optical soundtrack are pristine is that they never were exposed to the full-on blast of a projector bulb for repeated screenings. The sliver of picture might never have been hit with any light at all, and the soundtrack would have been hit with the relatively dim and fleeting light of an exciter lamp.

None of this is meant to rule out the possibility that chemical baths and processing peculiarities have played their part, too. I only mention this in hopes it brings you closer to an answer.

Posted by Allan Broadfield (Member # 2298) on May 19, 2014, 04:42 PM:

Once the cyan and yellow layers have faded, that's that. With eastman colour prints the magenta is the most stable, other manufactured stocks may vary, but basically you're stuck with your red print.

Posted by Dominique De Bast (Member # 3798) on May 19, 2014, 05:20 PM:

David, I remember that I readed it is not good for films to be exposed at an excessive projector light (but I don't know if the light or the heatness or both arms the stock). That was written in an article comparing filming at 18 fps and at 24 fps. One of the advantage of the second speed was that the film would stay less time exposed to the projector lamp. I don't know how scientific this advise was but it seems to go in the sense of your theory.

Posted by Allan Broadfield (Member # 2298) on May 20, 2014, 02:18 AM:

The exposure to strong light obviously speeds up the process of fading. In the lab we used filters extensively for printing purposes and sometimes if neutral density filters etc. were in short supply we would print up our own using normal print stock, but this was only a shortstop measure as these would fade quite rapidly.

Posted by Osi Osgood (Member # 424) on May 20, 2014, 01:15 PM:

Great posts folks. I had never thought of that a possibility (constant lamp exposure causing fading), it would be interesting if that is in fact, a fact ...

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