Re: Controlling Contrast in Colour C-41 --> RA4 Printing

Alan Smithee wrote:

I'm starting to set the gears in motion for adding colour to my darkroom and
it got me thinking. How does one control contrast changes in C-41 --> RA4
color printing? Is it done in paper or filtration. Given (I'm told) one
shouldn't alter the contrast (why?!) when processing the film, what "grade"
does C-41 film aim for? 2 or 3? Thx.



When printing, you can increase color saturation (and thereby contrast?) by use of the Anderson Method. Quoting myself from a post back in 2001:

The technique is described in the booklet "Perfect Color Printing" from
Photo Techniques Magazine.  It was stated there for the EP-2 method, but
I have successfully applied it to RA-4 chemistry.

Here are the steps:

1.    Expose as normal
2.    Develop in color developer as normal
3.    Fix in B&W fixer for 2 minutes
4.    Wash thoroughly
5.    Bleach in 2.5% solution of potassium ferricyanide (w/ 7g potassium
bromide) for 2 minutes +
6.    Wash thoroughly
7.    Redevelop in color developer
8.    Either repeat from step 4 to further increase saturation or use
bleach-fix as normal
9.    Wash and dry.

The reason it works is explained by Dr. Chapman in his article "The
Photochemistry of the Anderson Method" contained in the same booklet.
There are always unused color couplers in conventional color emulsions.
Recycling the silver halides allows the activation of further color
couplers from the appropriate dye layer.


Francis A. Miniter
.