35mm Reversal Films are NOT Negatives

35mm slides are specially mounted individual transparencys intended for projection onto a screen using a slide projector. The most common form was the 35mm slide, with the image placed in a 2x2" plastic or cardboard mounts. The slides are made from reversal type film.

A reversal film is a type of photographic film that produces a positive image on a transparent base. The film is processed to produce transparencies or diapositives instead of negatives and prints. Reversal film is produced in various sizes, from 35mm roll film to 8x10" sheet film.

Reversal film is sometimes used as motion picture film, mostly in the 16mm, Super 8 and 8mm formats, to yield a positive image on the original film placed in the camera. This avoids the expense and slight degradation of image quality resulting from using a negative film, and copying to a positive, to produce a print for projection. This does not mean that there was no processing involved. The film still had to be run through a number of steps to get from the film that was exposed in the camera to the final film that was put into the cardboard or plactic mounts and then shown in slide projectors. The E-6 process is a chromogenic photographic process for developing Ektachrome, Fujichrome, and other color reversal slide photographic film. The E-6 process superseded the earlier E-3 and E-4 processes. The E-3 process used light for reversal, and produced transparencies that faded more quickly. The E-4 process used chemicals that are environmentally unfriendly and the highly toxic reversal agent Tertiary Butyl-Amine Borane.

The process people were used to, before the introduction and popularity of digital cameras, was to use negative film in the camera. When the film was all taken, then the film was taken to a film processor, such as Walgreens, and the negative was "developed" and then printed to a positive paper print.

Internagatives

35mm slides never were a "negatives". There was a process where negatives could be created from the slides. These were called "internagatives."

1. The camera operator shoots a positive image and the film ends up as a negative.
2. The original negative is printed onto stock that comes out as an interpositive. Often, two interpositives were made, one to be archived and one to continue through the process.
3. The interpositive is color timed (to balance the scenes) into the internegative.
4. The internegative makes the positive release print.

Cibachrome or Ilfochrome Prints

Ilfochrome (formerly known as Cibachrome, sometimes known as "C Prints") is a dye destruction positive-to-positive photographic process used for the reproduction of slides on photographic paper. The prints are made on a dimensionally stable polyester base, essentially a plastic base opposed to traditional paper base. Since it uses azo dyes on a polyester base, the print will not fade, discolor, or deteriorate for a long time. Characteristics of Ilfochrome prints are image clarity, color purity, as well as being an archival process able to produce critical accuracy to the original slide.