- E-6 process
The E-6 process (often abbreviated to just E-6) is a
Photographic processingsystem for developing Ektachrome, Fujichrome, and other color reversal (slide) photographic film.
Unlike some other color reversal processes (such as Kodachrome K-14) that produce positive transparencies, E-6 process can be done manually by amateurs with the same equipment that is used for processing black and white negative film or C-41 color negative film. However, unlike black and white developing, the process is very temperature sensitive; and the use of a tempered water bath to stabilize the temperature at 100 °F for the first developer and first wash is recommended to maintain process tolerances.
By contrast, the
K-14 processand older Kodachromeprocesses are much more complex than E-6, and is currently performed in only one specialized processing plant world-wide (Dwaynes Photo Service in Parsons, Kansas); with all other Kodachrome cine and K-Lab processors shut down and decommissioned.
E-6 generally replaced the E-3 and E-4 processes in
1976. The older 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 (TBAB).
Six-bath compared to three-bath
There are two families of E-6 processing chemistries. The original and standard that is used in commercial labs employs a six chemical bath process. The 'hobby' type chemistry kits (such as sold by
Tetenal) use three chemical baths, the first developer, a combined fogging bath and colour developer solution, and the pre-bleach, bleach and fixer bath solutions. [Rinses, washes, stop baths and stabilizer/final rinse (the final step of the process) are not counted in the counting of baths when describing both the conventional six bath and hobbyist three bath processes.] However, the three step process suffers from poor process control (i.e. color shifts and color crossover), especially due to insufficient bleaching and/or fixing in the bleach-fixer ("blix") mixture.
Conventional six bath processing
The basic steps for developing color transparency films using process E6 are as follows. [cite web | url=http://www.kodak.com/global/en/service/Zmanuals/z119.shtml | title=Process E-6 Using KODAK Chemicals, Process E-6 Publication Z-119 | publisher=
; First developer bath: 6:00 @ 100 °F/38 °C. This uses a
potassium hydroquinone monosulfate- phenidoneblack & white film developer, with the preferred form of phenidone being 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone (13047-13-7). The first developer forms only a negative silver image in each layer of the film: No dye images are yet formed. The first developer is one of the most time and temperature critical steps in Process E-6, because it controls contrast.
; First wash: Water stop bath, 2:00 @ 100 °F/38 °C. Originally this step used an acetic acid stop bath, but was replaced with a water-only bath for process economy, with concomitant slight adjustment downwards of first dev strength.
; Reversal bath: Fogging bath, 2:00 @ 96-103 °F/36-39 °C. This bath prepares the film for the color developer step. In this bath, a chemical reversal agent is absorbed into the emulsion, with the chemical reaction instantly taking place. The reversal process can also be carried out using 800
footcandle-seconds (8.6 klx·s) of light, which is used by process engineers to troubleshoot reversal bath chemistry problems such as contamination, as well as issues of low tank turnover as process volumes decline.
; Color developer bath: 6:00 @ 96-103 °F/36-39 °C. Process-to-completion step, which contains
CD-3developing agent as the main constituent. When film enters the color developer, the bath acts on the chemically exposed silver halide to form a positive silver image. (The metallic silver image formed in the first developer, which is a negative image, is not a part of the reaction that takes place in this step. What is being reacted in this stage is the "leftover" of the negative image, that is, a positive image.) As the color development progresses, metallic silver image is formed, but more importantly, the color developing agent is oxidised. Oxidised color developer molecules react with the color couplers to form color dyes in situ. That is, color dye is formed at the site of development in each of the three layers of the film. Each layer of the film contains different color couplers, which react with the same oxidised developer molecules but form different color dyes. Variation in color developer pH causes color shifts on the green-magenta axis with Kodak E100G & E100GX and Fujichromefilms and on the yellow-blue axis with older Ektachrome films. [cite web | url=http://www.kodak.com/global/en/professional/support/techPubs/e4024/e4024.jhtml | title=KODAK PROFESSIONAL EKTACHROME Films E100G and E100GX | publisher= Kodak| accessdate=2007-07-04]
; Pre-bleach bath: 2:00 @ 90-103 °F/32-39 °C. This bath was previously called "conditioner", but was re-named pre-bleach in the mid 1990's to reflect a major change in removing the formaldehyde from the process used in the final rinse. The pre-bleach bath solution has
formaldehydeacting as a dye preservative and EDTAto "kick off" the bleach. The pre-bleach bath also relies on carry-over of the color developer (i.e. no wash step between the color dev and pre-bleach baths) to function properly; as well as carry-over from the pre-bleach to bleach baths.
; Bleach bath: 6:00 @ 92-103 °F/33-39 °C. This is a process-to-completion step, and relies on carry-over of pre-bleach to "kick off" the bleach. The bleach converts metallic silver into silver bromide, which is converted to soluble silver compounds in the fixer. During bleaching, iron (III) EDTA is changed to iron (II) EDTA (Fe3+ EDTA + Ag+ + Br−→ Fe2+ EDTA + AgBr) before fixing. Kodak also has a recipe (process variant) which uses a higher concentration of bleach and a 4:00 bath time; but with process volumes declining this is uneconomical.
; Wash step (optional): Rinses off the bleach and extends the life of the fixer bath. This wash step is recommended for rotary tube, sink line and other low volume processing.
; Fixer bath: 4:00 @ 92-103 °F/33-39 °C. This is a process-to-completion step.
; Second fixer stage (optional): Using fresh fixer. The archival properties of film and paper are greatly improved using a second fixing stage in a reverse cascade. [cite web | url=http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=007dXZ | title=Why two step fixing is a Really Good Thing | first=Dan | last=Schwartz | publisher=Photo.net | date=
March 8 2004| accessdate=2007-07-04 Note that this is the Photo.Net discussion thread of the 1998 technical paper by Dr. Michael J. Gudzinowicz. ] Many C-41RA (rapid access) minilab processors also use 2 stage reverse cascade fixing for faster throughput.
; Final wash: 4:00 @ 92-103 °F/33-39 °C.
; Final rinse: 1:00 @ 80-103 °F/27-39 °C. Up until the mid 1990s, the final rinse was called a stabilizer bath, since it contained
formaldehyde. Currently, the final rinse uses a Photo-Flo-style surfactant, and miconazole, an anti-fungal agent.
; Drying: Drying in a dust-free environment.
* [http://www.kodak.com/global/en/service/Zmanuals/z119.shtml Kodak Process E-6 Publication Z-119]
* [http://www.kodak.com/global/en/service/Zmanuals/z6.shtml Kodak Q-LAB Process Control Handbook] - more details than processing manual Z-119
* [http://msds.kodak.com/ehswww/servlet/COM.td.ehswww.servlet.FileStreamServlet?P_LANGU=E&P_SYS=2&P_SSN=2867&P_REP=00000000000000000002&P_RES=3208 Kodak Professional First Developer Replenisher, Process E-6] (PDF)
* FujiFilm USA [http://www.fujihuntusa.com/html/pro_product_bulletin.asp Product Bulletin Library] technical data sheets
* [http://www.bonavolta.ch/hobby/en/photo/e6.htm E-6 process] by Claudio Bonavolta
* [http://www.processc22.co.uk Process C-22] UK and Europe
* [http://www.filmrescue.com Film Rescue] USA and Canada
* [http://www.rockymountainfilm.com Rocky Mountain] USA
* [http://www.super8camera.com/processing.html E-6 Ektachrome] DIY processing super-8
Wikimedia Foundation. 2010.
Look at other dictionaries:
Process theology — is a school of thought influenced by the metaphysical process philosophy of Alfred North Whitehead (1861–1947) and further developed by Charles Hartshorne (1897–2000). While there are process theologies that are similar, but unrelated to the work … Wikipedia
Process Oriented Psychology — (POP) refers to a body of theory and practice that encompasses a broad range of psychotherapeutic, personal growth, and group process applications. It is more commonly called Process Work in the United States, the longer name being used in Europe … Wikipedia
Process architecture — is the structural design of general process systems and applies to fields such as computers (software, hardware, networks, etc.), business processes (enterprise architecture, policy and procedures, logistics, project management, etc.), and any… … Wikipedia
Process mining — techniques allow for the analysis of business processes based on event logs. They are often used when no formal description of the process can be obtained by other means, or when the quality of an existing documentation is questionable. For… … Wikipedia
process — pro·cess / prä ˌses, prō / n 1: a continuous operation, art, or method esp. in manufacture whoever invents or discovers any new and useful process...may obtain a patent therefor U.S. Code 2 a: procedure (1) see also … Law dictionary
Process philosophy — (or Ontology of Becoming) identifies metaphysical reality with change and dynamism. Since the time of Plato and Aristotle, philosophers have posited true reality as timeless , based on permanent substances, whilst processes are denied or… … Wikipedia
Process management — is the ensemble of activities of planning and monitoring the performance of a process, especially in the sense of business process, often confused with reengineering. [Jörg Becker, Martin Kugeler, Michael Rosemann (eds.).Process Management. ISBN… … Wikipedia
Process design (chemical engineering) — Process design is the design of processes for desired physical and/or chemical transformation of materials. Process design is central to chemical engineering and it can be considered to be the summit of chemical engineering, bringing together all … Wikipedia
Process isolation — is a set of different hardware and software technologies designed to protect each operating system process from other processes. It does so by preventing process A from writing into process B. Process isolation can be implemented by with… … Wikipedia
Process (engineering) — Process engineering refers to engineering which is collaborative and concerned with completing a project as a whole.emiconductor devicesIn the electronics industry, especially for those building ICs, some technologists can be referred to as… … Wikipedia
Process integration — is a term in chemical engineering which has two possible meanings.1. A holistic approach to process design which considers the interactions between different unit operations from the outset, rather than optimising them separately. This can also… … Wikipedia