From gnu.mat.uc.pt!news.rccn.net!nova.puug.pt!EU.net!news.sprintlink.net!news.onr.com!usenet Sun May 21 21:51:12 1995 Path: gnu.mat.uc.pt!news.rccn.net!nova.puug.pt!EU.net!news.sprintlink.net!news.onr.com!usenet From: geoffs@onr.com Newsgroups: rec.photo.advanced Subject: More than you want to know about E-4 Date: 19 May 1995 05:31:33 GMT Organization: Onramp Access, Inc. Lines: 233 Message-ID: <3phafl$8ao@Sierra.onr.com> Reply-To: geoffs@onr.com NNTP-Posting-Host: onramp2-11.onr.com X-Newsreader: IBM NewsReader/2 v1.09 The following is the complete description of the Ektachrome E-4 process. I've noticed a fair amount of interest from individuals in using Kodak IR Ektachrome film so I thought that I'd post this process for anyone who might be interested. Doesn't seem worth the effort for amateurs (or pros, for that matter)! IR Ektachrome is one of the only films around that still uses the E-4 process; all others having been converted to use the E-6 process. There were a very few commercial labs running E-4 a few years back; I don't know if any independent does it any longer and I don't believe that even Kodak provides development for this film. It is used for aerial work and in some forensic applications so Kodak probably sells just enough to specialty users to keep this emulsion process alive. I would imagine that these users have access to decent enough labs to control the critical temperatures and PH ranges that this process demands. I make no claims to the accuracy or viability of the process information provided and will accept no responsibility for any failures resulting from its use. I scanned it in from a book. Furthermore, the reader is advised that some of the chemicals used are highly toxic and require a high degree of competancy in hazardous materials handling to avoid injury or death. With all of that said, can anybody clue me in as to why Kodak never reformulated their IR Ektachrome to use the much safer/somewhat simpler E-6 process? I'm guessing that the color couplers and/or emulsion sensitizers used in the E-4 process were somehow not economically adaptable to newer methods. E-mail me with comments or answers, I'm interested in the chemistry of photography and its history. -Geoff- *************************************************************************** EKTACHROME E-4 Special attention is drawn to the warnings as to the extremely noxious nature of some of the chemicals used in these formulae. Their use should not be attempted by workers unaccustomed to handling such chemicals. Process E-4 when introduced presented two departures from earlier processes: 1.) Re-exposure before colour development was discontinued; reversal is effected by chemical fogging of the emulsion during colour development. This solution contains an organic chemical-TBAB (tertiarybutylaminoborane)-which enables all parts of the emulsion which have not been developed by the black-and-white first developer to react to the colour developer. TBAB is very toxic and must be handled with the greatest care to avoid contact with the skin and respiratory organs. It should be noted, however, that in the substitute formula for the colour developer this additive may be dispensed with, provided the film is re-exposed to light in the customary fashion; the colour characteristics of the film are practically unaffected. 2.) To improve the mechanical resistance of emulsions destined for Process E-4 treatment at 29 deg. C, it is necessary to treat them in a preliminary hardening bath containing, in addition to formaldehyde, 2,5-dimethuxytetrahydrofuran (DMTF), a liquid whose vapour is very aggressive in its action upon the respiratory system and eyes, and is very rapidly absorbed by the cutaneous tissues. It is therefore essential to avoid any contact with the liquid. Should the skin become contaminated with it, the affect ed part should be very thoroughly washed for 15min. Should the eyes exhibit symptoms of irritation a doctor should immediately be consulted. So far as formaldehyde is concerned, amateurs will already be familiar with its very active tanning and irritant p roperties, and we are confident that they will automatically take the utmost precautions. Formulae Pre-hardener (pH: 4.9-5.0) 6-nitrobenzimidazole nitrate 0.03g Sodium or potassium bisulphate 0.8g 2,5-dimethoxytetrahydrofuran 5.0ml Sodium sulphate (anhydrous) 136.0g Formaldehyde (35-40% solution) 30.0ml Potassium bromide 3.0g Water to 1000.0ml Neutraliser (pH: 5.1-5.2) Hydroxylamine sulphate 20.0g Acetic acid, (98-100% glacial) 10.0ml Sodium acetate, (3H20) 24.0g Potassium bromide 16.0g Sodium sulphate (anhydrous) 25.0g Potassium metabisulphite (crystalline) 5.0g Sodium hydroxide 6.0g Water to 1000.0ml First developer (pH: 10.1-10.3) Calgon 2.09 Metol 6.0g S odium sulphite (anhydrous) 50.09 Sodium carbonate (anhydrous) 30.0g Hydroquinone 6.0g Potassium bromide 2.0g Sodium thiocyanate 1.3g Sodium hydroxide (pellets) 2.0g Potassium iodide (0.1% solution) 6.0ml Water to 1000.0ml Stop bath (pH: 3.4-3.6) Sodium acetate (3H2O) 5.3g Acetic acid (98-100%glacial) 30.0ml Water to 1000.0ml Colour developer (pH: 11.8+/-0.2) Calgon 2.0g Trisodium phosphate (12H2O) 40.0g Sodium hydroxide (pellets) 5.0g 1,2-diaminoethane (hydrate) 3.8ml or ethylenediamine sulphate (crystalline) 7.6g Benzyl alcohol (35% solution*) 10.0ml Tertiary butylaminoborane (TBAB) 0.1g Citrazinic acid 1.3g EDTA Na4, EDTA tetrasodium salt 3.0g Sodium sulphite (anhydrous) 5.0g Potassium bromide 1.0g Potassium iodide (0.1 % solution) 20.0ml Water to 1000.0ml Add to Color Developer before use: Kodak CD-3 11.3g *Benzyl alcohol, 35% solution benzyl alcohol 35.0ml Diethylene glycol (digol) 45.0ml Water to 100.0ml Bleach (pH: 6.6-7.0) Potassium ferricyanide 112.0g Potassium bromide 24.0g Disodium hydrogen orthophosphate (12H2O) 62.0g Monosodium dihydrogen orthophosphate (anhydrous) 15.6g Sodium thiocyanate 10.0g Water to 1000.0ml Fixer (pH: 4.5-4.9) Ammonium thiosulphate (crystalline) 120.0g Potassium metabisulphite (crystalline) 20.0g Water to 1000.0ml Stabiliser Formaldehyde (35-40% solution) 3.0ml Wetting agent (10% solution) 10.0ml Water to 1000.0ml Procedure 1.) Preliminary hardener 3min 29.5+/-0.5 deg. C 2.) Neutraliser 1min 28-31 deg. C 3.) First developer 6min 29.5+/-0.25 deg. C 4.) First stop bath 2min 28-31 deg. C Normal room lighting may be resumed 5.) Wash, running water 4min 27-32 deg. C 6.) Colour developer 9min 27-32 deg. C 7.) Second stop bath 3min 27-32 deg. C 8.) Wash, running water 3min 27-32 deg. C 9.)Bleach 5min 27-32 deg. C 10.) Fixer 6min 27-32 deg. C 11.) Wash, running water 6min 27-32 deg. C 12.) Stabiliser 1min 27-32 deg. C Dry 43 deg. C Total 49min Notes A.) Recommended agitation is continuous for the first 1 5sec, then 5sec every minute. B.) Complete transparency of the film is reached only when it is perfectly dry. It should be noted that it is permissible to dry off the film temporarily after completion of Stage 5. The film should then be stored in diffused light or preferably in total darkness until processing is to be completed . C.) The pre-hardener chemicals should be dissolved in water at 38-40 deg. C with continuous agitation until solution is complete. At least 10min must be allowed to elapse before use to allow the DMTF to become transformed by hydrolysis into succinicaldehy de, a powerful gelatin tanning agent. The solution becomes effective after this transformation is complete. D.) Should it not be possible to obtain the commercial ethylene diamine (1,2-diaminoethane) hydrate (80% ethylene diamine) (beware of noxious fumes) for the colour developer, the sulphate, which is easier to handle, may be used. In this case, the pH-value may need to be adjusted by adding a few millilitres of a 10% solution of caustic soda. The TBAB, supplied by Kodak Limited in pellet form, should be crushed in a little water, using a glass rod or small pestle, then the remaining solution added. The TBA B can be dispensed with if the usual procedure of reversal by exposure to light is followed (see above). E.) It should be emphasised that any contamination of one solution by another must absolutely be avoided. As the intermediate washes have been reduce d to a strict minimum, all utensils employed in processing must be thoroughly cleansed and dried before use for a succeeding solution. F.) The two stop baths shouId be kept sepa rate to avoid contamination. G.)Time of development in the first developer should be increased in accordance with the use it has had. For 20exp 35mm films, or approximately 0.37sq ft material per film, the times should be as follows : 1-4 films 6min 5-7films 6min 15sec 8-10 films 6min 30sec 11-12 films 6min 50sec H.) This process is suitable for use with Kodak Photomicrography Color Film PCF 2483 and Ektachrome Infrared. These are the only current Kodak E-4 process materials on the general market. Keeping properties and working capacities: Solution Keeping Working capacity per litre time 135-20 135-36 120 Pre-hardener 4 weeks 12 7 8 Neutraliser 3 months 12 7 8 First developer 3 months 12 7 8 colour developer: without CD-3 6 weeks - - - with CD-3 4 weeks 12 7 8 Stop baths 6 months 12 7 8 Bleach 6 months 18 10 12 Fixer 6 months 12 7 8 Stabiliser 6 months should be used fresh Other manufacturers' materials compatible with the E-4 process: As a result of the worldwide dissemination of the Kodak Ektachrome E-4 process, many other manufacturers produced materials suitable for processing in E-4 solutions. By now all have been superseded by E-6 process films: particular care should be taken to distinguish between older E-4 and the current process materials. By now most E-4 process materials are many years out of date. From: David Josephson Newsgroups: rec.photo.darkroom Subject: Re: E-2 process ...is actually E-4 (sorry) Date: 7 Apr 1996 20:53:11 GMT Organization: Josephson Engineering Lines: 27 Message-ID: <4k99vn$l0o@samba.rahul.net> References: <4k90rs$ie1@hasle.sn.no> NNTP-Posting-Host: waltz.rahul.net NNTP-Posting-User: davidj Status: OR In <4k90rs$ie1@hasle.sn.no> Per Hilton writes: >Thanks to you all for advice on the E-2 process. >As nobody believed this could be only 20 years old, I checked >the film again, just to discover that it's (eeeeh) E-4. I am >really sorry about this. >The problem remains, however. How do I develop this film??? Same problem; no one makes E-4 any more. There is a modern equivalent called EA-5, which is run at high temperature for high speed aerial film processing, and ME-4, which is used for some motion picture films. EA-5 at 85 degrees F is essentially identical to E-4. There is a lab in Colorado, Rocky Mountain Film, that will do single rolls in EA-5, for about $20 each. The other alternative is to make or buy some EA-5 prehardener and neutralizer, which makes the emulsion able to withstand further processing, and then immediately run it in E-6. (A major difference between E-4 and E-6 films, maybe *the* major difference, is that the E-4 films are not hardened in manufacture while E-6 films are.) The recipes for the prehardener and neutralizer are on Bengt Halliger's homepage at http://math.liu.se/~behal/photo. Nothing particularly exotic in either chemical except hydroxylamine sulfate in the neutralizer. I am waiting for some of this from Formulary and will then try it with some aerial Ektachrome I have. -- David Josephson / Josephson Engineering / San Jose CA / david@josephson.com