Develop Slide Film With C-41 Chemicals AKA E-6(-)

In this instructable, we will develop slide film that normally uses the E-6 chemical process with a standard black and white film developer and color negative film process (C-41) chemicals. The results will be a positive image that will approach the quality of E-6 developed film. I like to call this "E-6(-)" since there are definite minuses to the process. The example I use is for 35mm film, but the process will work for any size. I certainly didn't invent this technique. The basics have been kicking around the internet for some time, but as E-6 processing seems to be disappearing, an alternate technique may be of some use.

Although this technique has been kicking around the web a while, a Flickr thread that I can't find right now reignited my curiosity. I hope you find it an interesting alternative developing process.

What is slide film?

Slide film is also called positive, chrome or transparency film. The end result is that the film becomes the final positive image and is usually mounted in cardboard slide mounts. These "slides" are then used to bore teenagers in home slide shows of weddings and vacations from years gone by. That use has long been supplanted by online photo slide shows, but the film has been kept around due to its remarkable sharpness and clarity.

How is slide film normally developed?

Slide film is normally sent out to labs where the film is processed by a chemical process that is known as E-6. The process is one of the more complex chemical development regimes now that the K-14 (Kodachrome) process is a thing of the past. Home developers can buy kits that can have as many steps as six; however some of the steps can be combined to make it at least as simple as standard C-41 development.

Why would I want to develop my slide film this E-6(-) way?

A few reasons;

1. C-41 chemicals are usually less expensive than E6 chemicals. For example from Freestyle Photo, the Tetenal Colortec E-6 Kit - 1 Liter is $70 and will develop 12, 36 exposure rolls of film. The Tetenal C-41 Color Negative Processing Kit - 1 Liter costs $50 and will process the same number of rolls.

2. For home developers, the E-6 chemicals have a shorter shelf life than C-41 onced mixed to working dilutions. Although the E-6 chemicals are getting better, they still do not have the staying power of C-41 chemicals when stored.

3. E-6 processing is becoming increasingly difficult to source. C-41 is far more available and can be found in nearly all places around the world.

4. My personal reason for pursuing this technique is that I have a bunch of very out of date slide film that will not perform that well even with proper E-6 processing. I wanted to find a cheap way to produce the funky results I value. This technique meets my very stringent standard of "good enough."

What will be the results of this "special" E-6(-) process?

Well, it won't be perfect. Since this process simulates the E-6 process with less expensive chemicals, the sharpness and saturation of the film will be there, but the image will have a definite cast (a uniform color shift). Although the cast would definitely be noticeable if you were projecting the slides, the image can easily be corrected when scanning the slides. I've found that the "auto color correction" feature fixes 90% of the images. The rest can be tweaked in the image manipulation software of your choice.

Isn't this just "Cross-Processing?"

Yes with an "and" or no with a "but." Full cross processing of slide film is just processing slide film as C-41. This is a popular thing to do in fashion, artistic and hipster communities. It results in garish, oversaturated, high contrast and other worldly negative images. Processing slide film as black and white will yield a black and white negative. This special E-6(-) process will yield a positive image just like E-6 processing.

Slide film + E-6 = Color Slides

Slide film + C-41 = Color negatives + extreme color shifts + extreme contrast

Slide film + Black and White Processing = black and white negatives + poor contrast

Slide film + B&W +C-41 = Color slides + slight color shifts

Step 1: Stuff You Will Need

If you are use to home processing film, you probably already have all the hardware you require for E-6(-). The "software" is any C-41 developing kit and any black and white developer.

Slide film (usually marked E-6 processing).
Changing bag or dark room.
Developing reels (plastic or steel).
Developing tank (plastic or steel).
Thermometer, immersible.
Scissors.
Can or bottle top opener.
C-41 developing kit with solutions mixed as per the instructions.
B&W film developer mixed as per instructions (Xtol used in this case, but any should work).
Distilled (deionized) water.
Rinse aid (e.g. photoflo).
Latex or nitrile gloves.
Adhesive tape.
Spring clothespins.
Access to an area with hot and cold running water.
About an hour of time.
Film scanner.
Negative sleeves.

Note on film: Different film types react differently to this process. The example here is Kodak Elite Chrome which ends up with a blue cast as the final product. Other chrome films can come out nearly normal colors with little to no color correction necessary so your results may vary...in fact they probably will vary! That is half the fun.

Step 2: Heat Up Your Chemicals

If you are like me, your chemicals are stored at room temperature and have to be heated up to operating temperature. For this E-6(-) procedure, the temp of the developers and blix is 102 degrees Fahrenheit or 39 degrees Celsius.

Mix your solutions (both C-41 and Black and White developer) according to the instructions on the packaging to make working strength solutions.
Take your working strength solutions of a black and white developer, color developer, and blix and put them in a sink or tub.
Fill the sink with 110 F (43 C) water and let sit for about 15~20 minutes. Load your film while you are waiting (next step).
After allowing the solutions to heat up, check the temp of the water bath with your thermometer. Add hot water until the water bath is about 105 F (41 C). Keep an eye on the temperature. The solutions will be at the correct temperature when the water bath reaches 102 F (39 C).
A modern alternative to getting your exact temperature is using a Sous Vide. This is an immersion heater that recirculates water and heats it to exact temperatures. It is used for cooking things in the water bath (in a plastic pouch) so it can be used to heat your chemicals to the exactly needed temperatures.

Note on temperature: For you C-41/E-6 purists, the correct temperature is exactly 100 F (~38 C) however, most home development kits recommend 102 F and have the temperature drift by as the solutions inevitably cool while agitating.

Step 3: Load Your Slide Film

No real trick here. Just load the film onto the developing reel of choice and insert into the developing tank. Of course you will need to do this in complete darkness, either in a darkroom or changing bag. It is a nice relaxing activity while your chemicals warm up to operating temperature.

Gather your materials and place in the changing bag in an easily rememberable configuration.
Pry off the cap on the film can with your bottle opener. If you have snap caps from self loaded film cans, you can get those off with just your fingernails.
Extract the film and clip off the leader with scissors. I like to clip off the sharp corners on the end of the film. This makes it easier to insert into the steel or ratchet type reels.
Insert the film into your development spirals.
Put spirals into the developing tank.
Close tank and bring into daylight.

Step 4: Prewet/Preheat

The purpose of this step is to get the film ready for developing by bringing the temperature of the tank, spirals and film up to operating temperature (102 degrees F (39 C)) and to get the emulsion saturated and ready for developer.

Adjust the water out of the tap to 102 degrees F (39 C)and fill the development tank.
Add a drop of photoflo to the tank. Optional really, but I like to do this to break the water tension that can keep the entire film from getting wet.
Agitate for 30 seconds.
Place the tank in the tub of water until you are ready to develop the film. Try to arrange your process so the film does not spend more than five minutes with this presoak. Ideally, you just want it to warm up for a minute or so everything is wet and the temperature to the same as your solutions.
When you pour out the prewetting water, it may have a color (pink, purple, red, etc). Don't worry too much about this...it is usually just some antihalation dye that comes out of the emulsion.

Step 5: First Developer - Black and White

The first developer is the most important step in E-6 processing and is no different here! If the developer is too active, the final image will be too thin (too faint) and if the activity is too slight, you will get too much color dye to the extent that you can't see through the slide! The exact opposite of what you would think if you are use to developing black and white....remember this is "reversal" film and a lot of things are backward!

What black and white developer should I use?

Ideally, you would use E-6 first developer, but as noted before, it can be expensive and hard to source. Theoretically, any black and white film developer should be fine. I used Xtol for my experiments as it is what I normally use for developing my black and white film. Xtol is a fine grain, environmentally friendly solvent type developer that seems to work well in this process. HC-110 also has been reported as having acceptable results. It may be interesting to try compensating developers or even staining developers to convert exposed silver halide grains (the latent image) into metallic silver. It may introduce a different look into the final image?

Put on your rubber gloves and safety glasses. None of these chemicals is more dangerous than ones found underneath your sink, but safety is always a priority!
Your Xtol should be at stock strength and heated to the standard development temperature for C-41 and E-6....102 degrees F (39 C).
Pour out your pre-wetting water (don't be alarmed by the color).
Before your tank has time to cool, pour in the Xtol developer and agitate for the first 10 seconds.
Put the tank back into your water bath when not agitating to keep the temp as constant as possible.
Agitate (4 inversions) every 30 seconds for the entire length of development.
Develop for 12 minutes.
Pour out developer.
Fill the tank with hot water (again 102 degrees F (39 C)) [this is your "stop" bath].
Agitate for 30 seconds, empty, refill, agitate for 30 seconds and empty.

Step 6: Fog Your Slide Film

This is a counterintuitive step if you are use to developing black and white. You have to fog the film with light before it is fixed! In normal E-6 processing, this step is usually done chemically, but here we are doing it the old fashioned way...with photons! I used a halogen light source (my bathroom light), but most any light will do, however it has been reported that full sunlight may not be that great. Perhaps UV rich sources should be avoided?

Remove the film spirals from the tank in normal room light. You will notice the negative image on the emulsion side of the film.
Unreel the film, but leave the end still clipped into the steel reels. For the ratchet type system, you have to disassemble the reel to get the film out.
Hold the film emulsion side toward the light source and run the film along to ensure it is all fogged. I fogged my film at 6 inches from a 40 watt halogen bulb (my bathroom light) for 2, 20 second passes (40 seconds altogether).
Once you are satisfied that your film is totally fogged, load it back onto the reel. Plastic ratchet type reels are a little more problematic. The film and the reels must be completely dry before reuniting them. It does not affect the process much, but figure in drying time into your workflow.
Place loaded reels with film back into your processing tank.

An alternate method at this point would be to dry the film, reroll it into a film cartridge and drop off at your friendly C-41 one-hour photo lab. The lab workers will be confused when seeing positive images coming out of the machine instead of negatives. May cause some uncomfortable conversations?

Update: Kelly-ShaneF suggests that you use a full spectrum bulb to fog the film rather than a tungsten bulb. He believes that this would cut down or eliminate the blue cast of the film. I have not tried this, but will and report back if this does work.

Step 7: Second Developer - Color Developer

For the rest of the process, you will more or less be following the instructions on the C-41 kit. This second developer is the color development stage of the process. The color developer for the C-41 kit is a complex chemical known as CD4. Although it will develop the color couplers in the slide film, it will not do it as well as the native E-6 developer that has CD3 developers. This may be one of the reasons that the final slides have a color cast to them.

Refill the development tank with hot water to warm the film and reels as in previous step.
Pour out hot water and pour in color developer from the C-41 kit.
Use the same agitation regime as the black and white developer
Develop as indicated on the kit instructions, 3.5 minutes (3 minutes and 30 seconds).
Pour out developer and fill the tank twice with hot water.

Step 8: Bleach and Fix or Blix

Some C-41 kits have a separate bleach and fix step, but this one has you combine into a "Blix." Functionally, it is all the same unless you are doing bleach bypass or some other process. The bleach converts the metallic silver image back to silver halide then the silver halide is removed in the fixer. Using a Blix saves a step.

Empty your tank of wash water.
Fill with blix and use the same agitation regime as the developers.
Blix for 6.5 minutes (6 minutes and 30 seconds).
After blixing, pour out the blix and refill the tank with hot water. Empty and refill 2 or 3 times.

Step 9: Stabilize

The C-41 kit includes a stabilizer of hexamine (Hexamethylenetetramine to be exact) to stabilize the dyes in C-41 film. This is a substitute for formalin that use to be used in the bad old days. Hexamine is made by reacting formaldehyde and ammonia, but is much less toxic than the reactants. In E-6, the stabilizer is call the "pre-bleach" and is used between the color developer and the bleach step (it use to be called the "conditioner" before the formula was changed). Will the differences in the composition and and place in the workflow affect the longevity of the final product? Not sure...my 1 year old slides seem to be good shape with no deterioration of the image, but longer term stability may be in question... Since this process is primarily for scanning and not projecting, you might as well do this as soon as you can so you have a digital copy.

Pour out any wash water from the tank and pour in stabilizer (this can be done at room temperature).
Agitate for 15 seconds and stabilize for 1 minute.
Pour out stabilizer.
Pour a solution of distilled water and photoflo into the tank (this prevents water spots in hard water areas).
Empty the tank of the distilled water and photoflo.

Step 10: Dry

Your slide film will come out of the process looking a little milky. This will slowly clear as it dries.

Take your film out of the tank and shake each reel sharply to get as much water off the film as possible.
Take the film off the reel and hang in a dust free environment. Place a clip on the bottom of the film strip so it does not curl as it dries.
Once dry, cut into strips and slide into negative saver pages.

Theoretically, you can mount the slides in cardboard or plastic slides for projection. However, the slides are likely to have a color cast that will distract from your slide show. I suggest scanning instead of boring your kids with a slide show.

Step 11: Scan

Due to either the age of the film or more likely the use of a substitute color developer, the Elite Chrome came out with a cyan color cast. It almost looks like tungsten film shot under daylight conditions without a filter. Luckily, the cast seems even across image and easily corrected. If you are good with curves, you can probably get very close to the actual color pallet, but I've found that using the Epson scan software color restoration feature (color autocorrection in other software) will give you a 80-90% solution.

Preview your film using the color positive setting on your scanner.
Select the images you want to scan and turn on the "color restoration" feature in the software.
If the image isn't to your liking, open up the curves feature and try your luck.
Even if the image isn't 100% correct, scan anyway and deal with it later in photoshop or other software of your liking.

Step 12: Examples (Good and Bad)

For these examples I used film that was many years out of date so it is obviously not in its prime already. That was exacerbated some poor exposure in some images. They come from a variety of cameras...some with dubious optics and I may have scratched a roll during the fogging step. Excuses, excuses!

Other than the scanner software auto color correct, I have not altered the images. If you are good with curves, you can probably get much better colors out of these scans. Underexposure fared the worst of the conditions that these were shot with. Slide film has a notoriously narrow latitude so the photographer might be more to blame that the film or processing.

Although not perfect, this technique could be a useful alternative to developing your slide film as E-6 gets less available and more expensive.

Step 13: Way Ahead

This non-standard slide film development technique will probably need some experimentation to get reasonable results. Some variations I might try in the future to improve or at least vary the technique:

Use compensating developer for the first developer.
Use a staining developer as the first developer.
Use RA4 (color paper developer) as the color developer (contains CD3...slide film's native developer).
Use a separate bleach and fix for bleach bypass processing.
Stabilizing between the color developer and the blix.

Anyway, it certainly has been interesting learning about photographic chemistry during the process.