The E-2 process and E-3 process are outdated processes for developing Ektachrome reversal photographic film. The two processes are very similar, and differ depending on the film. Kodak sold kits that could process either kind of film.
Ektachrome film has three separate light-sensitive layers; each layer is sensitive to a different group of wavelengths corresponding to red, green, and blue colors. When the film is exposed, each layer records a latent image based on its sensitivity. A yellow filter prevents blue light from exposing the green- and red-sensitive layers, which have some sensitivity to blue light. [1]
Films are processed at 75 °F (23.9 °C) with a tolerance of only ±0.5°F; exceeding these limits could cause color shifts. [2] : 30–31 The steps are:
| Step | Schematic | E-1 (1946) [3] | E-1 (1955) [2] : 30–31 E-2 (1955) [3] E-3 (1959) [3] | Description | ||||
|---|---|---|---|---|---|---|---|---|
| Time (min) | Temp. | Time (min) | Temp. | |||||
| 1 | First developer |  | 15 | 68 °F (20 °C) | 10 | 75 °F (24 °C) | This is a conventional black-and-white developer, which develops the exposed portions as a negative. | |
| 2 | Stop bath / rinse | 1 | 65–72 °F (18–22 °C) | 1 | 73–77 °F (23–25 °C) | |||
| 3 | Hardener | 5–10 | 66–70 °F (19–21 °C) | 3–10 | 73–77 °F (23–25 °C) | |||
| 4 | Reversal exposure |  | varies (typically 5 sec/side) | The film is removed from the tank and thoroughly exposed with a bright light for either 5 seconds on each side, or each end of the reel is exposed for 15 seconds at a distance of 1 ft (0.30 m) from a No. 2 photoflood. This step sensitizes the remaining silver halide crystals for the colour developer. Replace in tank, though the lid was no longer required. | ||||
| 5 | Wash | 5 | 65–72 °F (18–22 °C) | 3 | 73–77 °F (23–25 °C) | Using running water | ||
| 6 | Colour developer |  | 25 | 66–70 °F (19–21 °C) | 15 | 73–77 °F (23–25 °C) | This develops the now exposed silver bromide, and simultaneously activates the dye couplers in the three colour-sensitive layers of the film. | |
| 7 | Wash | 5 | 65–72 °F (18–22 °C) | 5 | 73–77 °F (23–25 °C) | Using running water | ||
| 8 | Clear | 5 | 66–70 °F (19–21 °C) | 5 | 73–77 °F (23–25 °C) | To remove pink stains left by the colour developer. Solution saved for fixing bath (step 12). In the E-1 process, this is noted as a "clearing and fixing bath." | ||
| 9 | Rinse | 1 | 65–72 °F (18–22 °C) | 1 | 73–77 °F (23–25 °C) | Using running water for at least 30 seconds, but not more than 90 seconds. | ||
| 10 | Bleach |  | 10 | 66–70 °F (19–21 °C) | 8 | 73–77 °F (23–25 °C) | To convert all the developed silver into compounds that are made soluble in the fixer | |
| 11 | Rinse | 1 | 65–72 °F (18–22 °C) | 1 | 73–77 °F (23–25 °C) | |||
| 12 | Fix |  | 5 | 66–70 °F (19–21 °C) | 3 | 73–77 °F (23–25 °C) | To remove all the developed silver. In the E-1 process, this is noted as a "clearing and fixing bath." | |
| 13 | Wash | 10 | 65–72 °F (18–22 °C) | 8 | 73–77 °F (23–25 °C) | Running water | ||
| 14 | Stabilizing / Wetting agent rinse | 1 | 65–72 °F (18–22 °C) | 1 | 73–77 °F (23–25 °C) | Using Kodak Photo-Flo to remove water droplets | ||
| 15 | Dry | not specified | varies | <110 °F (43 °C) | Same as for black-and-white films | |||
The original Ektachrome process introduced in 1946 used similar steps with different durations; the total processing time was approximately 90 minutes. [4] It was renamed to E-1 when the E-2 process was introduced in 1955 for ASA 32 Ektachrome, followed by E-3 for ASA 50 Ektachrome in 1959. [3]
Films designed for E-2 and E-3 are prone to fading because of the instability of the color dyes. [5] [6] The processes were phased out in 1974 in favor of E-4 (which was introduced in 1966), and two years later E-6 was introduced which remains in use to this day.
Film stock is an analog medium that is used for recording motion pictures or animation. It is recorded on by a movie camera, developed, edited, and projected onto a screen using a movie projector. It is a strip or sheet of transparent plastic film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast and resolution of the film. The emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a very short exposure to the image formed by a camera lens is used to produce only a very slight chemical change, proportional to the amount of light absorbed by each crystal. This creates an invisible latent image in the emulsion, which can be chemically developed into a visible photograph. In addition to visible light, all films are sensitive to X-rays and high-energy particles. Most are at least slightly sensitive to invisible ultraviolet (UV) light. Some special-purpose films are sensitive into the infrared (IR) region of the spectrum.
The following list comprises significant milestones in the development of photography technology.
Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system introduced in the mid-1970s. A closely related ISO system is used to describe the relationship between exposure and output image lightness in digital cameras. Prior to ISO gaining traction the best known systems were ASA in the U.S. and DIN in Europe.
110 is a cartridge-based film format used in still photography. It was introduced by Kodak in 1972. 110 is essentially a miniaturized version of Kodak's earlier 126 film format. Each frame is 13 mm × 17 mm, with one registration hole. Cartridges with 12, 20, or 24 frames are available on-line. Production variations sometimes have allowed for an additional image.
Kodachrome is the brand name for a color reversal film introduced by Eastman Kodak in 1935. It was one of the first successful color materials and was used for both cinematography and still photography. For many years, Kodachrome was widely used for professional color photography, especially for images intended for publication in print media.
Photographic paper is a paper coated with a light-sensitive chemical formula, like photographic film, used for making photographic prints. When photographic paper is exposed to light, it captures a latent image that is then developed to form a visible image; with most papers the image density from exposure can be sufficient to not require further development, aside from fixing and clearing, though latent exposure is also usually present. The light-sensitive layer of the paper is called the emulsion. The most common chemistry was based on silver halide but other alternatives have also been used.
The E-6 process is a chromogenic photographic process for developing Ektachrome, Fujichrome and other color reversal photographic film.
C-41 is a chromogenic color print film developing process introduced by Kodak in 1972, superseding the C-22 process. C-41, also known as CN-16 by Fuji, CNK-4 by Konica, and AP-70 by AGFA, is the most popular film process in use, with most, if not all photofinishing labs devoting at least one machine to this development process.
Instant film is a type of photographic film that was introduced by Polaroid Corporation to produce a visible image within minutes or seconds of the photograph's exposure. The film contains the chemicals needed for developing and fixing the photograph, and the camera exposes and initiates the developing process after a photo has been taken.
In infrared photography, the film or image sensor used is sensitive to infrared light. The part of the spectrum used is referred to as near-infrared to distinguish it from far-infrared, which is the domain of thermal imaging. Wavelengths used for photography range from about 700 nm to about 900 nm. Film is usually sensitive to visible light too, so an infrared-passing filter is used; this lets infrared (IR) light pass through to the camera, but blocks all or most of the visible light spectrum.
Ektachrome is a brand name owned by Kodak for a range of transparency, still and motion picture films previously available in many formats, including 35 mm and sheet sizes to 11 × 14 inch size. Ektachrome has a distinctive look that became familiar to many readers of National Geographic, which used it extensively for color photographs for decades in settings where Kodachrome was too slow. In terms of reciprocity characteristics, Ektachrome is stable at shutter speeds between ten seconds and 1/10,000 of a second.
The E-4 process is a now outdated process for developing color reversal (transparency) photographic film, which was introduced in 1966.
A chromogenic print, also known as a C-print or C-type print, a silver halide print, or a dye coupler print, is a photographic print made from a color negative, transparency or digital image, and developed using a chromogenic process. They are composed of three layers of gelatin, each containing an emulsion of silver halide, which is used as a light-sensitive material, and a different dye coupler of subtractive color which together, when developed, form a full-color image.
Color motion picture film refers both to unexposed color photographic film in a format suitable for use in a motion picture camera, and to finished motion picture film, ready for use in a projector, which bears images in color.
K-14 was the most recent version of the developing process for Kodak's Kodachrome transparency film before its discontinuation. It superseded previous versions of the Kodachrome process used with older films.
Duplitized film was a type of motion picture print film stock used for some two-color natural color processes. It was introduced by Eastman Kodak around 1913. The stock was of standard gauge and thickness, but it had a photographic emulsion coated on both sides of the film base instead of on one surface only.
Leopold Damrosch Mannes was an American musician, who, together with Leopold Godowsky Jr., created the first practical color transparency film, Kodachrome.
Redscale is a technique of shooting photographic film where the film is exposed from the wrong side, i.e. the emulsion is exposed through the base of the film. Normally, this is done by winding the film upside-down into an empty film canister. The name "redscale" comes because there is a strong color shift to red due to the red-sensitive layer of the film being exposed first, rather than last [the red layer is normally the bottom layer in C-41 film]. All layers are sensitive to blue light, so normally the blue layer is on top, followed by a filter. In this technique, blue light exposes the layers containing cyan and magenta dyes, but the layer containing yellow dye is left unexposed due to the filter. E-6 film has also been used for this technique.
Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography, it consists of silver halide crystals dispersed in gelatin. The emulsion is usually coated onto a substrate of glass, films, paper, or fabric. The substrate is often flexible and known as a film base.
Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and resolution of the film.
Processing of older Ektachrome films including Process E-3:
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