E-3 Vs E-4 Processing

[Tanner Martin]

Is anyone aware of the major differences between E-3 and E-4 Color processing? I am gonna be running a few experiments this summer with a ton of old stock ektachrome I have and I have an old "How to Process Movie Film" Handbook detailing the entire E-3 process (step times, formulas for the hardner, etc). I am well aware this may be a fools errand but I want to try just for the heck of it. However, a good chunk of the ektachrome I have is made for the E-4 process. I have some for the E-3, but I was curious if I can use the E-4 stock I have in an E-3 process, and what the major differences there are that would change the process significantly.  Thanks for any help!

[Martin Baumgarten]

The major difference is in the Color Developer and the film itself.   Other than that, they two processes are the same, both requiring Pre-Hardner and Neutralizer and rinse, prior to actual film development.  You can use a modern E-6 process done at room temperature to avoid the chemical prehardening of the film emulsion, and then just use a B&W Rapid Film Fixer with Hardener in the Final Step. You can do this also if using the 3-step E-6 formulation since the purpose is to harden the film emulsion even though it's already been fixed by the Bleach-Fix stage (BLIX).  Done at room temperature in the 72F to 75F range, the emulsion will be fine.  Do take care to make sure all chemistry and washes are all well within 2 degrees of range, or the unhardened film can suffer emulsion reticulation or mosaic cracking.  Allow to air dry and avoid heat afterward.  The E-6 formulations list times and temps for processing at room tempertures.  However, if the film has NOT been freezer stored all these years, it will suffer from a serious loss of emulsion speed, contrast, and color dye shifting, so you'll have to compensate by cutting back First Developer time, often by at least half the recommended time, perhaps even more.  The good thing here is that at room temperature, the development times are long, so cutting them down still gives you enough time for even development.  I would do a small test first of a short piece of film, preferably shooting a Color Chart and Gray Scale Chart, to get yourself in the correct range.  Don't expect miracles from such very old film though!  Good luck!