ECN-2 film, often known as movie film or cine film, and made widely available in the form of Cinestill branded film, is great for what it is, but using Cinestill film in C-41 always bugged me. The colors always seem a bit off, it comes off as overly grainy, and the lack of antihalation layer on Cinestill really doesn’t work for me in daylight. Also, Cinestill branded film is expensive! Given that I’ve seen movies shot on film, I knew that these problems weren’t the fault of the actual Kodak ECN-2 film itself. It’s due to lack of remjet and cross processing. So, why not just shoot the proper film and process it properly? Well….

Proper ECN-2 processing, assuming you’re wanting to process less than 1000 feet at a time, is uhh.. inaccessible. I know of no labs in the US that will process it properly for short 36 exposure rolls. The best I know of is some labs will handle remjet for you and then process it in C-41. So, why not process it properly at home though? Well, problems there as well. QWD (Quiet We’re Dreaming) finally came out with a long awaited proper ECN-2 kit. It’s expensive but I’ve heard good reviews and good results. The alternative to QWD is the bulk packages of ECN-2 chemicals direct from Kodak (or through B&H special order). Given that developer etc doesn’t last forever once mixed, it would seem unwise to buy a 50 liter kit of ECN-2 developer, etc. So, that leaves us with the final solution of mixing the chemicals ourselves in small batches.

But if this is so difficult, then why shoot ECN-2 film at all? Honestly, because it’s great:

• In the modern world of a new film each year being discontinued, ECN-2 film is very secure. It might be replaced with an improved version, but given the volume (tens of thousands of feet, or more) that movie makers use, there is little chance of these films being discontinued anytime soon due to lack of revenue from it

• It provides a unique appearance unmatched by C-41 or E-6 films. It gives an extremely flat color profile across the exposure range. There is minimal color crossing when done properly. This means you don’t get something like the “typical Ektar blue shadows”. You get darker shadows, until there’s no more density.

• Combined with the above point, ECN-2 is a lower contrast film in its design. This allows for massive latitude in post-processing to make the film convey the look you’re after. It also means that it’s very good at capturing high contrast scenes without skies clipping out or introducing weird colors in post-processing

• If you buy it by the 1000ft can, it’s by a large margin the cheapest pictorial 35mm color film you can get.

• For Kodak 50D specifically, there is absolutely nothing matching the fine grain of it in color negative. It’s finer grain than Ektachrome 100 in my experience.

• It (and the ECP-2 cine printing process) is the only modern color process for which Kodak publishes official formulas and instructions on how to create the processing chemicals from scratch. And mixing it like this is very economical, if you don’t mind stocking up on a large list of chemicals. If you’re a homebrew enthusiast, this actually makes more sense than C-41 as long as you can put up with the annoyance of remjet removal

• It’s unmistakably “cinematic”. There is just a different appearance to the final result of these films. I can’t exactly describe what it is. I love C-41 films and I love E-6 films, but neither can exactly emulate this in my experience.

UPDATED PROCESS

While I thought I had this process figured out, I kept having strange problems. Specifically with water spots, white powder appearing on the film, etc. So, I am working on testing and changing this process to use an alternative carbonate+bicarbonate prebath and to do the remjet removal after the stop, rather than after the bleach. Make sure to strain all liquids through a filter. After several runs, my bleach is still good but running it all through a coffee filter revealed that it had a visible amount of remjet contamination. Also, instead of using microfiber cloths, I’ve had much better luck using simple coffee filters. Coffee filters are nearly lint-free, will contain no chemicals or dyes (unlike most cloths), and are cheap and disposable. Remjet is practically impossible to wash out of a cloth, so disposable makes sense in this context. I need to do more test runs (I had an issue with strange base color) before I revamp this blog post, but if you’re looking at doing this for the first time yourself and experience weird problems on the base side, this could very well be it.

Materials and Ingredients

Anyway, so lets get into the process. Unfortunately unless you want to order huge volumes from Kodak, you’ll need to mix everything from raw chemicals. I’ll provide the names of suppliers in the US. If you know of sources in the EU or other regions for these chemicals, please leave them in the comments. Here is the list:

• CD-3 — The color developing agent used in ECN-2. Can not be substituted with CD-2 or CD-4. Available in reasonable quantities at Artcraft

• Sodium bromide — You can substitute the more easily available potassium bromide, but it is believed to cause the bleach to decay faster and you’ll have to do a molar conversion. Available at Artcraft and Photographer’s Formulary

• Sodium sulfite — Very common developer preservative. Available at Artcraft, Photographer’s Formulary, and likely many other places including swimming pool supply stores

• Sodium sulfate — Not the same as sulfite! Used to harden film emulsions. Available from Photographer’s Formulary, and many eBay and Amazon sellers

• Potassium Ferricyanide — Often used for B/W bleaches as well. Available at Artcraft and Photographer’s Formulary and likely other places. Do not mix with strong acids!

• Sodium Carbonate — Common alkali, also known as washing soda. Often sold in the most stable/preferred monohydrate form, but sometimes in the anhydrous form. Available from Artcraft, Photographer’s Formulary, many eBay sellers, Amazon, etc.

• Sulfuric Acid — I have 10N which is just about 40%. By making substitutions you can use down to 2.5N. Available from Photographer’s Formulary (note: DEA form required, 48%) and a few eBay chemical sellers and Amazon sellers. Expect slow ground shipping no matter how you get it. Always use EXTREME caution including gloves and eye protection during handling. Keep baking soda nearby to quickly neutralize spills including on your skin. Note if you use vinegar for stop bath, and an unbuffered bleach, you can exclude this. I recommend using it if you have it on hand or can easily source it, but if it’s too hard to get, then it shouldn’t be too bad to skip.

• Borax — Yes, the laundry soap additive. Used as a weak alkali and buffering agent. Commonly available even at supermarkets

• Sodium hydroxide — Commonly known as lye and used in soap making. An extremely strong alkali. Available widely from Amazon, eBay, etc. Use caution when handling including gloves and eye protection and immediately wash off any spills!

• Ammonium thiosulfate — Fixing agent. This is only sold in liquid solutions. I use the 60% solution available from Photographer’s Formulary

• Kodak anti-calcium #4 — Chelating agent to prevent calcium stains on film. I’ve found no safe replacement and given previous calcium problems, I would not recommend skipping it unless absolutely necessary (and if so, then make sure to use distilled water for every solution). It can be bought in large quantities from B&H or Kodak directly, or in small quantities from Photographer’s Formulary.

• Sodium metabisulfite — An acidic form of sulfite. Often used in winemaking and as a food preservative. Easily available in many places for this purpose

• Sodium bicarbonate — Also known as baking soda (NOT baking powder), used as a mild alkali buffering agent. Very widely available. Good to have nearby anytime you’re messing with sulfuric acid

• Kodak AF-2000 — Proprietary anti-fogging agent sold as a liquid. According to some sources, will give some correction to the natural color balance of the ECN-2 film to make it closer to correct. Seems to not really matter for scanning but might matter for ECP-2 printing the film. It’s too expensive for me to invest in and I get good results without it. Available at B&H and Kodak direct in very large quantities. No alternate source for small quantities has been found. Should not be substituted with benzotriazole or other anti-fogging agents, other than potentially Kodak AF-1 which is even harder to source and a contact explosive

• Photo-flo — Drying agent; prevents water marks and makes the film dry faster. Kodak specifically recommends a different harder to source drying agent, but Photo-flo seems to work fine. Available from B&H, Freestyle, local photo stores, etc. Can be substituted with other drying agents most likely from different brands.

• Distilled water — Always mix at least the developer and final rinse using distilled water. If skipping the anti-calcium, then use distilled water for all of the components

• pH test strips — You can either buy “universal” 0-14 pH test strips or separate sets of test strips for alkali and acidic ranges. I use the universal type that are accurate to 0.5 pH. I don’t recommend pH meters unless you know what you’re doing and have a high quality one. Some pH meters use silver electrodes which will be ruined by the chemicals used here. Typically pH strips are available for less than $20 for 100 strips on Amazon. The exact pH points needed is 6-7, 0.5-1.5, and 9-10.5

• A good set of stir rods or a magnetic stirrer. I highly recommend a magnetic stirrer if you can afford it. It makes things so much easier

• A set of beakers and/or graduates. You’ll need to measure up to 1L

• A scale accurate to +/- 0.1g

• A set of syringes. I use simple 1ml “disposable” syringes but don’t actually throw them away after each use. These are used for fine tuning of the pH in the bleach and for measuring out anti-calcium

• A microfiber cloth. You could potentially substitute this with something else lint free such as coffee filters or lens cleaning cloths.

• Funnel. For putting the solutions back into bottles of course

• Coffee filters. Needed for straining the alkali solutions to prevent contamination with remjet

• Gloves, always use these for anything with film chemicals honestly

• Eye protection/goggles. For handling the sulfuric acid

Formulas

Now lets get to the formulas. There’s many alternate formulas that Kodak publishes and some “read between the lines” recommendations about little additions to their formulas. I’ve broken these down into formulas which use the most easily available chemicals, and should present with best stability given those constraints.

Note: Add all chemicals exactly in the order specified. Measure the pH of each solution after mixing to ensure it is at least close to the correct pH. Also measure the pH of each solution occasionally before use to ensure it has not shifted too much.

ECN-2 Developer:

• 850ml of distilled water, 80-100F

• anti-calcium #4, 2ml

• sodium sulfite, 2g

• sodium bromide, 1.2g

• CD-3, 4g -- mix for 10m

• sodium carbonate anhydrous, 25.6g —OR— sodium carbonate monohydrate, 30g

• sodium bicarbonate, 2.7g

• Kodak AF-2000, 5ml (can be excluded)

• distilled water to make 1L

• pH 10.25

• Capacity: Reported to be up to 8 weeks with care, and 16 rolls of film. Conservative estimate to me would be 12 rolls of film and 3 weeks in a closed bottle. Solution will discolor to pale yellowish brown a few days after mixing, but this does not seem to affect results. Discard if it turns a deep brown. Some small amount of time compensation after a few rolls of film may help prevent shifts in results. pH will seemingly fluctuate and honestly is difficult to make sense of. Seems to rise in pH with age rather than decrease. May give more consistent results if solution is allowed to stand and “season” for 1-2 days after mixing.

ECN-2 Pre-bath:

• 800ml of water, 80-100F

• borax, 20g

• sodium sulfate, 100g

• sodium hydroxide, 1g — CAUTION

• Top to 1L with water

• pH 9.25 (note: should not be allowed to dip below 9 or remjet removal may be sub-optimal)

• Capacity: Likely will last practically forever, but maybe 40 roll of film capacity. Use occasional pH testing and remix when below pH 9

ECN-2 Stop:

• 900ml of water, room temperature

• Sulfuric acid 7N, 50ml -- OR -- Sulfuric acid 10N, 35ml -- OR -- 10ml concentrated sulfuric acid — EXTREME CAUTION! USE EYE PROTECTION, GLOVES, AND HAVE SODIUM BICARBONATE NEARBY TO NEUTRALIZE SPILLS QUICKLY

• Water to make 1L

• pH 0.8 to 1.5

• Capacity: Likely will last practically forever but maybe only 20 roll of film capacity. Use occasional pH testing and remix when above pH 1.5

• Note: final solution will be irritating upon skin contact. Always use gloves with every solution in ECN-2 for safety.

Note: If using very dilute sulfuric acid here, you may use less starting water

According to QWD, you may substitute this with 250+750ml of household (3%) vinegar to water. However, using acetic acid (what’s in vinegar) will introduce color casts or uneven stopping of development. This is according to a former Kodak chemist who worked with the process extensively. Basically if they could’ve excluded sulfuric acid, they would’ve, but it was deemed impossible. However, clearly since QWD uses this for their process and theres been no complaints, it can give good results regardless. I use sulfuric acid because I have it on hand, but would use vinegar if I didn’t.

ECN-2 Bleach:

• 900ml water, 90-110F

• potassium ferricyanide 40g

• sodium bromide 25g

• borax 1.5g

• Top to 1L with water

• Add 5-20ml of 2.5N sulfuric acid (prepare by diluting 1+3 10N sulfuric acid) CAUTION, SEE NOTE

• pH 6.5 +/- 0.5 — Do not let dip under 6!

• Capacity: Unknown, likely months or years of shelf life and capacity for 40 films. Use occasional pH testing and check for retained silver on the film (will give a grey shimmer to highlights)

CAUTION: This is an imprecise formula! Being careless with adding acid to this solution can result in HYDROGEN CYANIDE GAS RELEASE, an extremely toxic chemical which can be deadly! This is probably the most sketchy part about mixing this formula! Add 2-3ml of sulfuric acid at a time and check the pH using the pH test strips. Add more, then check pH again and so on, until it is 6.5. If in doubt, aim for just below a neutral 7. If you prefer to not mess with this at all, then exclude the borax and use no sulfuric acid. This will yield a bleach with far lower stability however due to lack of buffering.

ECN-2 Fixer:

I believe you could substitute this with something like Kodak C-41 fixer if you have it on hand, but this is what Kodak recommends.

• 700ml water, 70 to 100F

• anti-calcium #4, 2ml

• ammonium thiosulfate 58%, 185ml —OR— Ammonium thiosulfate 60%, 181.3ml

• sodium sulfite, 10g

• sodium metabisulfite, 8.4g

• Water to make 1L

• pH 6.5 — Do not allow pH below 5.5!

• Capacity: Unknown, likely months of shelf life and about 20 films. Use occasional pH testing and regular hypo-check solution to test for exhaustion

ECN-2 Final Rinse:

I simply use Kodak Photo-flo or other wetting agent diluted according to instructions, using distilled water. Use the final rinse one-shot, discarding the amount used after each processing session. Can likely be substituted for Kodak C-41 Final Rinse. Do not use other C-41 “kit” stabilizer mixes. The pH aim here is 6.5 or neutral. In my experience photo-flo in distilled water will naturally give this pH.

If you experience calcium stains (water marks), then you can add 1ml/L or so of anti-calcium #4 to the final rinse. This seems to reduce the calcium stains I get (despite using distilled water everywhere) to reasonable levels.

Process

Now, with the hard part done, the actual process is quite simple and very fast. Note that the only absolutely time and temperature critical part is the developing step. Everything else is much more flexible, though you should stick to the minimum temperatures and otherwise not exceed 106F. Personally, I use a sous vide bath set to 106F and put all of the bottles in there. After about 1 hour it’s ready to use. I leave the developer in the bath until ready for that step and pull all of the other bottles out (note all of them are recommended for a max temp of 100F, not 106F, though I’ve not found it actually matters) and just leave them to sit at room temperature.

Note I’m writing these instructions for a hand tank, though they could easily be adjusted to a jobo or other similar continuous rotation setup. In such a case, use the same timing listed here but process like you would C-41 in regards to RPM/agitation amounts

Processing Steps:

1. Pre-bath, 30s with agitation, between 80F and 100F

2. Rinse 3-4 times using warm water. Note the water may be pink or grey

3. Repeat steps 1 and 2 two times in total. This will remove as much remjet as possible and you’ll likely have no problems with remjet coming off later. Strain the pre-bath through a coffee filter before placing back into the bottle.

4. Develop for 3m at 106F. I begin pouring into the tank at 3m10s, and pour out of the tank when the timer hits 0. Quickly tap the tank when you have completed the pouring to dislodge air bubbles. Then, agitate for 15s. Return the tank to the sous vide hot water bath. Afterwards agitate quickly 2 times every 15s and return to the bath. Pour out quickly when the timer hits 0. Pour the developer into a holding container such as a graduate rather than back into the bottle. Strain the used developer through a coffee filter before returning to the bottle to remove any remjet that came off in solution. This is never a problem in my experience, but good to do for safety. QWD recommends an additional 30s in the developer for each stop if desiring to do push development

5. Stop bath, 30s with agitation, between 80F and 100F. Have the stop bath bottle open and ready to go immediately after you’re done pouring out the developer. The transition between these steps should be as fast as possible. Delay can introduce color casts

6. Rinse 3-4 times using warm water. Note the rinse water may be pink. WARNING: Skipping this rinse before bleach may ruin your bleach, ruin your film with blue specks, and also cause a release of hydrogen cyanide gas! If unsure, rinse more than you need for this step.

7. Bleach for 3m between 80F and 100F. Timing is less critical here. Agitate 30s initially and then 4 times after every 30s. Note bleach will have a weak but distinctly unattractive smell. It is possible to do “skip-bleach” processing. If doing this, then do remjet removal after the fixing step.

8. Rinse for 5+ times or 1-2m using warm water. You can remove the top of the tank for this step. Rinse water will be yellow initially but should be clear by the end

9. Rem-jet removal. You can do this after fixing, but remjet is much easier to see at this stage. If possible use a bright light to see the remjet on the back of the film (the back will appear blue with black stuff that is easily rubbed off). Using gloved hands and running water, carefully remove the film from the tank and unreel the film. The emulsion will be fragile so don’t get careless. Start at one end of the film and using your gloved hands, pinch the film under the running water and pull it through your gloved fingers. Wash you gloved hands after each time to avoid contamination to the emulsion side.. Don’t use a lot of pressure, but enough to give a bit of resistance. Repeat this at least 3 times. Finally, do one last measure to remove any remaining remjet. Hang the film somewhere (where the emulsion side won’t touch anything) with the back facing you. Hold the bottom of the film (or the middle carefully) and wipe the back of the entire length of film using a wet microfiber cloth, do not rub the cloth on the emulsion side!. Repeat this at least three times. Do not allow the film to dry though! So don’t be too slow about doing this, less than 5m preferrably. Inspect film to ensure no remjet is visible. Repeat as necessary. Re-reel the film. For stainless reel it’s very easy to re-reel, but for plastic it may be difficult. If you have difficulty with plastic reels, submerge the reel in a container of water and reel the film up while under water. I haven’t tested that technique myself, but I’ve heard from many others that it works

10. Rinse a few more times to get the film back to being properly wet and wash away any remaining remjet gunk.

11. Fix for 2m, 80F to 100F. Timing is not critical here. Agitate 30s initially and then 4 times after every 30s. Note fixer should have a mild slightly sulfurous smell

12. Rinse for 3m using warm water

13. Submerge in the final rinse for 30s. Only gentle agitation is needed

14. Hang film to dry and pour a drink! You did it!

Note that typically there will still be some very minor remjet spots or calcium spots. These should be small enough to be easily patched out in scanning though. I personally would not strive for 100% perfection here as it’s very difficult to get to that level without a complex linear processing machine

In my experience, being careless with the emulsion side during remjet removal can lead to weird mottling. These will appear as small blue spots on your final scans. There is seemingly no way to remove these if they form. I believe these may occur because of remjet getting stuck in the emulsion. Treat the emulsion side with utmost care!! The emulsion is honestly not super fragile with modern films even at this stage, but if remjet gets into it and it dries, then there is no hope of removing it.