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Read more: http://www.cinematography.com/index.php?showtopic=48841Originally Posted by Martin BaumgartenThe process I use depends on the type and age of the KODACHROME film I am developing. For very old KODACHROME-II films and very old KMA-40 films, they are processed to a B&W Negative using conventional KODAK D-19 technical developer, with time and temperature based on what information the customer has provided to me about age and storage history. Otherwise, for most films exposed prior to 1985, I will process the films not longer than 3 minutes and at 68 F (20 C), with first having a 2 minute prewash stage. I used to use an anti-fog agent, but have not really noticed any benefit to doing so for very old films that suffer from severe age fog. Afterall, that silver has been ionized and will react to development, and no chemical added can distinguish between silver that has reacted to light energy or to radiant energy.
If a batch of films come in, I will test one first, and base the processing on my results. If films are severely age fogged, I will often lower the Developer temperature down to about 65 F so that I can still keep development time in the 2 min to 4 range. It's a delicate balance between getting images and getting nothing. You have to be careful to not make the times so short that you'll just get cloudiness in the images with little detail. Some films are so severe that to the eye, it looks like the film is completely black. But upon examination under a strong light, you will see the images. I transfer all films done this way to video for the customer, who gets back their processed film and usually the DVD. The films that yield a somewhat closer to normal density negative image, can be transferred via most any telecine method. The films that are so extremely dense will require a more conventional telecine transfer with a bright projector lamp in order to be able to see the image and render it to video.
B&W Reversal Processing of KODACHROME films: This really can only be done successfully with films that are in good condition, not too old, or have been cold stored prior to use, regardless of age. Otherwise, there isn't enough silver for the reversal stage due to the severe age fogging in old films, and the images will either be very faint with little detail, or nothing at all.....just clear film. To reversal process good KODACHROME film, just use the normal B&W Reversal process. Prewash the film 1 to 2 minutes prior to development, and you will have to push the development in the First Developer by at least 2 minutes over normal time. The reason is that KODACHROME will lose its effective filmspeed if processed to the exact time you would process Plus-X or Tri-X for example. If you do not compensate the time, then the final images will be too dark otherwise. IF you are using the newer KODAK D-94a formulation to process the film and the new permagenate Bleach solution, then you will have to conduct a test to determine your time in the First Developer based on density after processing, and also will have to extend the Bleaching time by twice as much in order to bleach out all the negative silver.
REM-JET Coating Removal: In the motion picture process, this is soaked to soften in a remjet removal bath stage, then buffed with buffing rollers at the tank exit stage while being rinsed with water at the same time. In manual processing, you will have to remove the remjet after all processing is completed. It is troublesome, and slow to remove. After the film has been properly washed free of the Fixer, soak the film in a solution of Borax & Water (2 to 4 tablespoons per Liter), at a temperature of 75 F to 80 F, for at least 5 minutes, longer if necessary. After soaking, remove the film from the processing tank or spiral reel, depending on what method you are using. Transfer the film to a takeup reel, and then place into a tray of the Borax solution. If you can make up a special plastic tray by gluing a small stud in the center upon which the reel can rotate, all the better. Then setup a rewind arm; I use a portable 3ft setup with 2 small Craig 8mm/16mm rewinds on a 3ft 2" x 4" board which I can clamp to the lab sink or countertop via a large C-Clamp. Use a good photo-grade sponge and have a 2nd tray of Borax solution, as you will pull the film from the holding tray, thru the sponge which you will keep soaked and submersed in the 2nd Tray, and the film will then pass to the Takeup Reel on the Winder Arm. The remjet backing should come off, just be careful to wind slowly and watch the removal upon takeup. Be advised, this is a very messy process, and you will have to rinse the sponge out many many times, usually after every 5 to 10 feet of film. It depends on how much came off during the processing itself, usually, not too much. Generally, you will have to wipe the film completely at least twice to get all the remjet off. Then once removed, you will have to wash the film for at least another 2 minutes to remove all traces of the Borax solution. Then use a Wetting-Drying Agent such as KODAK Photo-Flo Solution, chamois if desired and hang up onto a Film Drying Rack to dry.
NOTE: IF the remjet is very hard to remove, even after soaking for a long time, even if you have increased the solution strength by double, then you will have to use more physical force by squeezing the sponge harder and pulling the film thru just a couple feet at a time and checking for removal, and if not all off, backing the film and going over those 2 feet of film again, until the backing is off. On some very old films, you will find that there often are still small traces of the remjet backing, and even film cleaner won't remove it easily. For Newer and/or Cold Stored films, the remjet will come off.
SEPIA Tone: If you prefer a nice rich Sepia Brown Tone to the reversal image, then substitute KODAK T-19 Developer for the ReDeveloper. This is a simple solution of Sodium Sulfite and Water....but NOTE.....use plenty of fresh air, since not only does this stink of rotten eggs, but can be dangerous! No reversal exposure is necessary when using this Developer. The formula is as follows:
KODAK SULFIDE ReDEVELOPER T-19
Kodak Sodium Sulfide (Anhydrous) 20.00 grams
Water to make......................1.0 Liter
I have been able to use Sodium Sulfide Flakes, but they must be ground up prior to mixing using a mortar and pistol and it can be quite time consuming. If you use this, make sure you use a breathing mask and do the grinding in full fresh air.
Exact times, temperature, method, all depends on what chemicals are available to you in processing your own films, and also what processing method you are using: Rewind Tank, Reel & Trough, Rack & Tray, Spiral Reel & Tank etc. No secrets, just normal B&W Reversal Chemistry, either the original long time formulas, or the current D-94a process.
LASTLY, if you desire a NEGATIVE image instead of Reversal, you can make use any any conventional full emulsion speed continous tone Developer (e.g. D-76, Microphen, HC-110 etc) and adjust your process as necessary based on density results. I recommend shooting your own Control Strip so that you can fine-tune the Negative Development to whatever Gamma or Contrast Gradient you desire. Since most would be transferring the Negative images to Video with electronic reversal......a remote possibility is to print the film and strike a positive from it; but that is costlier.
Hope this is useful to you.
Martin Baumgarten - November 2010