8mm Forum: Red film tint

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Posted by Brian Collins (Member # 761) on June 05, 2009, 08:30 AM:

Why is it that on a number of films I transfer for people I always find some that has an all over red tint to them, I can over come most of the problem by putting them through a white balance proceedure first, but what causes this tint to appear, any answers? is it deterioration or in the original processing?

Posted by Martin Jones (Member # 1163) on June 05, 2009, 08:48 AM:

I presume you are talking about the overall red tint being on the film stock as received for transfer; the answer is simple...
Some film stocks will change colour towards red over time, both before and after processing and the conditions under which the film is stored will affect the speed at which this occurs. Of the many reels of film I have exposed in nearly 50 years of marriage only a few have tended to do this; Ilford (Regular 8) is particularly bad, AGFA Moviechrome (Super 8) has a slight tendency to it. All my Kodachrome, including the very first rolls(of my wedding) on Regular 8, still has clear original colour. And I have in my hand at this very moment a solitary roll of Regular 8 Agfa that I took in 1961/2 which looks as if I took it yesterday.
Martin.

Posted by John Whittle (Member # 22) on June 06, 2009, 10:06 AM:

You are seeing the dreaded cyan dye failure. Various stocks have this to a greater or lesser degree. The worst being any Eastman color print stock up through the 1970s. Some of these stocks will fade to the point that there is only a light yellow image left.

Ektachrome and other incorporated coupler reversal films also suffer, but the non-chromengenic films like Kodachrome (where the color couplers were introduced in processing) are stable as are Technicolor dye transfer (IB) prints.

John

Posted by Jon Anders Klausen (Member # 818) on June 07, 2009, 07:15 AM:

Is there a way to prevent the print getting more red?

I remember seing a documentary a few years back, about some fimlfanatics living in New York. In one scene, they visited a screeningroom, where the projectionist was about to screen a red print. Before he did it, he put som green (hair?)gel on the lens (or on the glass the film projected through). This made the film look a little better and not so red when projected in the screen. Anyone have experience with this?

Posted by John Whittle (Member # 22) on June 07, 2009, 09:06 AM:

Jon
Check throught the forum archive, this is a lot of information on this. Basically a filter will not help. If it's just a little red, you can add a filter (in this case cyan not green) but it will tint the highlights of the image. Working electronically in telecine you can do a bit more since you can set midtones, highlights and shadows on their own.

The other technique is to do silver seperations and then print them back with different exposures that will hold white and black, but that's very expesnive and as far as I know only done on 35mm.

As for stopping it, that's hard to do. Some think storing the film at zero degrees F will slow down the action. What is happening is that the chemical elements that make up the cyan in the color in the image aren't leaving, they're just turning clear thus reducing the density of the original and turning it red.

In Eastman color negative materials from the 50s and 60s, the problem is with the yellow layer going causing a printing imbalance toward the blue in the print. There again, silver seperations if made originally can be used to make a new dupe negative with proper color balance--at considerable expense.

This is one of the "little" problems with film such as nitrate base decomp, safety film vinegar syndrome and dye fading.

John

Posted by Douglas Meltzer (Member # 28) on June 07, 2009, 10:34 AM:

Jon,

Here's a link to a review I wrote of Wittner's color rebalance filter.

Doug

Posted by Brian Collins (Member # 761) on June 08, 2009, 03:51 AM:

Thanks Gents for the mine of information, when transfering them I go through my system that has a manual white balance that improves the colour and then a high resolution video processor which then gives an acceptable transfer to DVD depending on the state of the original film.

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