20 Year Old Negative Colouration

Question

I'm undertaking a family photo digitisation project. I've got a lot of Kodak Gold negatives from the mid 90s.

I've noted that these negatives tend to have a yellow cast to them, particularly ones that were taken in bright sunlight. The colour correction in Epson Scan can fix mildly affected negatives but on badly affected ones it leaves an unusable blue cast.

What causes this and is there a good way to deal with it, beyond manually trying to fix each frame? Interestingly the prints of the same pictures are fine, so I'm thinking for these I'll need to just scan the prints.

Here's some samples: https://i.stack.imgur.com/OlSKZ.jpg

Answer 1

If you must use a flatbed scanner, then use vuescan as the program to control the scanner.

With the professional version it it quite simple to find the correct color for the scan. Scan part of a negative that has no information (an empty frame or the space between to frames) and use that to set the black level.

Lock the exposure, scan again and set the color correction you like.

Then you can lock the settings and most likely the color correction will work for the whole roll.

Read how to use the advanced workflows: https://www.hamrick.com/vuescan/html/vuesc16.htm

Another great advantage of vuescan is that it will let you store a raw linear file with no color correction as a 16bit Tiff file, that you can then take to whatever image editor you use, and do the color balance there.

Never trust auto-correction, auto color or auto-anything.

Scanning the prints will not yield as great results as scanning a negative.

If you have a lot of negatives to scan consider getting a macro lens and a copy stand and a lightbox. You can digitize images much faster with a camera and at a much higher resoultion than with a flatbed scanner.

Save the images as raw files and color correct them in bulk using whatever raw conversion app you like (lightroom, darktable, rawtherappee, etc) where you can do proper color balancing.

Answer 2

Unless you are seeing something abnormal, all color negatives have a yellowish – orange cast. This includes the unexposed edges. This normal yellow – orange is called a “mask”.

The reason for the yellow – orange mask: Color films depend on three dyes that form the color image. These are yellow – magenta (red + green) – cyan (blue + green). We can make a marvelous yellow dye, an OK magenta dye, but the cyan dye is lousy. The yellow dye is a blue light blocker. The magenta dye is a green light blocker. The cyan dye is a red light blocker. The cyan dye should stop red light -- allowing green and blue light to pass. The problem is, to make the cyan dye strong enough, it unwantedly blocks some of the green and the blue. Not the dye we want.

We have searched for improved cyan magenta dye, but no cigar. This is because all three dyes must be transparent until commanded to blossom. All are nearly transparent, and this state is called leuco (Greek for transparent /blank). All are missing the same ingredient called CD4. This is a component of the developer solution. When the film is being developed, the CD4 combines with the leuco dye to form a full blown dye. To keep the developing process simple: one missing ingredient for all three dyes. That complicates by narrowing down the list of available dyes. Thus we are forced to use inferior cyan and not quite perfect magenta.

Yellow – orange mask to the rescue. The magenta and cyan dyes are intentionally colored a warm hue in their undeveloped state. As they develop, they blossom to full magenta and full cyan, Always surrounding them will be undeveloped dye. It is this undeveloped cyan and magenta dye that gives the negatives their orange – yellow coloration. This mask is not uniform. It is strong in the unexposed areas and weak in the exposed areas. Its job is to correct the deficiencies of these two dyes.

We can do this in a color negative because the negative is a means to and end -- i.e. making a print on paper. We can’t get away with this technique on a slide film.

So don’t blame the orange mask for your difficulty. I could be that your negatives are contaminated and stained. I don’t think so. You just need to find the right correction to apply to get a good color balance.