increasing saturation?

Hi

 

I've seen that in the past, before the advent of digital image processing, there

were ways to increase color saturation in much the same way photoshop would

increase it

 

For example, it was done in preprint probably using some kind of a printing

technique. Those old hyper saturated postcards from 70's are one example.

 

I was trying to figure out what would be the analog way of doing that.

 

The best thing that I came up with is having BW 3 color separations, then

printing each one to color print or film but with substracting the other two.

 

For example exposing one layer to the targed, then also exposing the inverse of

the other two. Which would in fact exagerate colors for that layer (say red),

then doing the same with other two layers, and all colors would be more saturated.

 

Is this how it was done?

I don't know how it is done, but I remember the process produced what were called "color matched prints" or "color corrected prints" for duplication in publications, and cost about 4 times more money than conventional printing. I don't know if that term would help you narrow your search or not. They sure were beautiful though.

Those rare people who made dye transfer prints knew how to do this. It is a complicated process of masking. Lets say you have a color transparency and you want to increase the red saturation. (It will work much better if you have a large format transparency.) Copy the transparency onto low contrast B&W film exposed through a red filter. Now make a copy color transparency exposing sequentially through red, green, and blue filters. For the blue and green filters, sandwich the low contrast negative mask with the original. With the red exposure, shoot without the mask. The degree of red saturation increase depends on the contrast of the mask. You could do this for the green and blue as well.

 

There are people who do something like this with color sheet film. Check out fatali.com. He doesn't say exactly how he gets his results, but he does say it is all chemical. I believe he must be using masks to get the results he does. BTW, looking at a 30x40 print of his is like looking through a window to another world.

Edgar, based on some of the questions and comments I've seen you make, I'd like to suggest that you might find the book, "The Reproduction of Colour" by R.W.G. Hunt very interesting. One edition or the other seems to often be found in larger libraries.

 

Back to your question. The simplest route to increased color saturation is probably to increase contrast. As far as I know, this always works (excepting very bright and very dark areas). In a 3-color system, balanced values for all colors is neutral; when one of the colors is out of balance with the others, then a color cast is visible. If you were to then increase contrast, the degree of "out of balance" will increase, causing the color to become stronger. Many of the colorful postcards I've seen DO appear contrasty, so maybe this is their main method.

 

Now, an interesting thing (to me, at least) has come to light. Looking through Hunt's book on this topic, I see that scanners existed in the 1940s. Having some keywords to search (internet) for, I find that electronic scanners were being used to being used to make color separations for Life magazine in 1950.

 

Here's a link, followed by an excerpt:

 

http://www.taga.org/members/ColorEssentials/10-ColorScanning.pdf#search='timelife%20springdale'

 

>> The first commercial scanner was based upon Eastman Kodak developmental work initiated by Alexander Murray during 1936. This project was taken over by the Springdale Laboratories of Time Inc. in 1946 with the objective of producing a device that would drastically reduce the four-week lead time then required for editorial process color illustrations. In 1949, an order was placed with the Austin Company to build six scanners. By August 1950, sixty percent of the editorial work for Life magazine, as well as work for Time and Sports Illustrated magazines, was being color separated via these color scanners. The age of commercial color scanning had arrived. <<

 

I imagine these systems had capabilities of undoing color problems, as this was mathematically understood prior to 1940 (at least by a guy name of Yule). The method would be not unlike the colored coupler masks in color negative films, which according to Hunt, was used in Kodacolor film in 1949. And it seems likely that similar methods could be used to change saturation.

 

Ron probably answered your question better; he explains well and lucidly. At any rate, the electronic equivalents of that masking could be used with the scan systems. Hopefully at least a few people will enjoy reading up on the history!

May not be exactly what you are looking for, but have you tried shooting E-6, and having it processed C-41? It creates a sort of surreal, hypersaturated color. Just a thought - something to maybe play around with. I'm sure you can find a more detailed thread on cross processing... I seem to remember you have to pull the exposure a stop or something along those lines. Your local pro lab probably limits the amount of rolls they are willing to cross process, as it can damage chemistry, or alternately, you could process it yourself.

Thanks but I'm not looking to get saturated colors, I just want to know how it was done before photoshop

Ron thanks for the detailed answer. That sounds like it would have worked. That's probably how photoshop saturation works too, constructed based on this masking technique.