Deficiencies in DIY C-41 Chemistry

[Wayne]

I have priced it out to $2.30/L for C-41 and $1.90/L for ECN-2. Of course it also means hundreds of dollars in equipment as well, even if you go the cheap route. At this point I have spent enough that I probably could have bought enough chemicals for a year of developing and saved myself the headache as well. So is it cheaper? Yes and no. And that's with the caveat that my C-41 is still not quite performing at the level I'd like. It outperforms the powder from cinestill in overall color balance but still lacks the punchiness in the reds and greens. That being said, I think home brewing is worth it if you are consistently developing ECN-2. It's cheaper, has less ingredients and I consistently get good results from the published EK recipe.

C-41 has proved more complicated, at least for me. My V4 (with the potassium iodide included this time) is certainly acceptable for use but creates a noticeably cooler tone when compared directly to the factory chems I have available. Still ironing that discrepancy out, although a cooler tone could be desirable depending on what you find to be your "ideal" image.

Other than an expensive pH meter that I chafe at and probably would not buy, I believe I have everything else that I need. So I don't think it would cost me hundreds, it would only cost me whatever I pay for a less expensive pH meter and calibration solutions, and the chemicals. I've never shot ECN and have no plans to. Since (what I consider) decent C-41 costs $30/liter, and only develops 8 rolls of 120 without reuse, and I don't reuse, anything under 10-15 bucks is quite attractive for DIY. $2.30 would be a dream! I could actually start shooting a lot again.

But it has to work as well as good commercial product, or it doesn't "make sense." Never tried Cinestill or any of the "off brands" because I don't trust them. Unless UNicolor is considered an "off brand."

Anyway I don't want to derail your thread and I hope you solve your issues, as that would be encouraging to me.

 

[koraks]

it seems like the savings over commercial products would be significant

Depends on where you source and what you source. I cannot privately make C41 developer meaningfully cheaper than the minilab Fuji C41 developer I've been using the past few years. So the 'not making sense' for me was also an economic issue. Indeed, as you said, there's the equipment, and if you factor in your time and the cost of film involved in testing/troubleshooting, things are even less attractive. The DIY route has always been a kind of Plan B for me, and it just never really promoted to plan A status...

Since (what I consider) decent C-41 costs $30/liter

Local supply varies massively across the planet, but I'd be surprised if you couldn't beat this price by a mile. Around here, 10l of Fuji C41 replenisher (which makes 12.5l of developer) costs something like €60. That's the smallest minilab quantity you can buy.
Kits of 500ml, 1000ml etc. are of course relatively speaking far more expensive. If you're cost sensitive, those kits aren't the best choice.

 

[Spektrum]

It was the low prices of Fuji C-41 chemicals that encouraged me to give up experimenting with my own C-41 developer.

In Poland, 10 liters of Fuji Hunt C-41 developer costs 177 PLN, and this price includes 23% VAT (we have one of the highest VAT rates in Europe). 177 PLN is equivalent to 41.60 EUR. I also had to buy a 1 liter starter for 90 PLN (21.20 EUR incl VAT), but this starter will probably be enough for about 66 liters of working solution. This chemical is manufactured in Belgium. Poland is many kilometers away, and I am sure, shipping the chemical isn't cheap. I don't understand why in the Netherlands, Belgium's direct neighbor, is so much more expensive. I understand that a Dutch seller has to make money, but the wholesaler where I bought it in Poland also makes money. And Polish sellers really do not spare their customers.

I don't want to irritate anyone here but the prices of Kodak films are also rather lower compared to e.g. MACODIRECT DE - a roll of KODAK GOLD 200/36 (expires 2027/04) costs 9.90 EUR (incl VAT). Recently they had a promotion for KODAK PRO IMAGE 100/36 films (expires 2025/12) and sold them for 6.12 EUR (incl VAT). I bought a whole bucket of these films.
I guess I should stop complaining about the price of color film here. I just keep worrying about how long these relatively lower prices will last.

 

[Wayne]

Depends on where you source and what you source. I cannot privately make C41 developer meaningfully cheaper than the minilab Fuji C41 developer I've been using the past few years. So the 'not making sense' for me was also an economic issue. Indeed, as you said, there's the equipment, and if you factor in your time and the cost of film involved in testing/troubleshooting, things are even less attractive. The DIY route has always been a kind of Plan B for me, and it just never really promoted to plan A status...

But did it give you the same high quality results, or was it just "adequate" after all your testing? Ah, ok, here's what you said: "results were just fine – I never did any very systematic comparisons with big-brand chemistry, but negatives and prints were by all means presentable and usable."

I'm just not sure if that is a 4.8 star endorsement or a 3 star endorsement. ;-)

Local supply varies massively across the planet, but I'd be surprised if you couldn't beat this price by a mile. Around here, 10l of Fuji C41 replenisher (which makes 12.5l of developer) costs something like €60. That's the smallest minilab quantity you can buy.
Kits of 500ml, 1000ml etc. are of course relatively speaking far more expensive. If you're cost sensitive, those kits aren't t

Economy of scale is only available to those who can afford it. It costs a lot more up front to buy in volume, and requires shooting more film too to avoid wasting it. When you are stuck buying small kits, its about $30 a liter. The Kodak 2.5 liter kit is slightly less, at $60, but all of it requires shipping costs too so its still $30/liter or more. So yeah, even 10 or 15 bucks a liter for DIY would be well worth it to me but only if the quality and consistency is there.

 

[koraks]

I don't understand why in the Netherlands, Belgium's direct neighbor, is so much more expensive.

I didn't shop around extensively for the very best price. I could probably get this for the same price you got it for. I took the price from a consumer-oriented retailer of analog photo stuff.

But did it give you the same high quality results, or was it just "adequate" after all your testing?

The Fuji chemistry is better. IDK how many stars that is.

It costs a lot more up front to buy in volume

Yeah, if you can't afford the $125 or so to start out, you're stuck.

Even easier than developing C41 is painting yourself into a corner. Just saying.

 

[Spektrum]

I didn't shop around extensively for the very best price. I could probably get this for the same price you got it for. I took the price from a consumer-oriented retailer of analog photo stuff.

Now I understand. I wrote about the wholesale price, and sales are only available to businesses. They won't sell this product to the average consumer. Besides, it's the cheapest price on the Polish market.

 

[koraks]

FYI, this is the source I quoted: https://fotofilmfabriek.nl/product-categorie/fotochemie/kleurenontwikkelaar/c-41-kleurenchemie/

Even easier than developing C41 is painting yourself into a corner. Just saying.

Btw @Wayne sorry if the above sounded a little terse, but your 'problem' seems like one that's also a matter of mentality. If you want to shoot color film, it's going to cost you, one way or another. Nobody can sweeten that deal, ultimately.

 

[Spektrum]

Other than an expensive pH meter that I chafe at and probably would not buy, I believe I have everything else that I need.

Unfortunately, an expensive pH meter is essential if you want to achieve decent results with DIY chemicals. Even the slightest difference in the pH of the developer solution can cause problems with contrast or color reproduction (especially red). This has been mentioned many times, probably even in this thread. You can buy a cheap pH meter, but it will likely break down quickly and could ruin a negative that could be very important to you. With C-41 developing, if something goes wrong during bleaching, you can bleach again. Similarly, you can use fresh fixer again to fix what was messed up by the wrong or expired chemicals. But you can't fix a badly developed film. I mean re-developing in the correct developer will not help. This will frustrate you and discourage you from further experiments.

 

[koraks]

I had forgotten about this experiment I did last year, but I remembered. Have a look at this:

The film is Kodak Ektar. Top two strips are developed in Fuji C41 chemistry, the same @originalwinslow showed in the box above. The bottom two strips are developed in DIY C41 developer, the formulation shown on my website but without the iodide. I did NOT measure or adjust the pH of the DIY developer, so it was likely off. The bottom strips are underdeveloped for sure compared to the Fuji-developed film. I have compensated for this in the digital inversion by simply lifting the curve - I did not touch the color balance. Another methodological issue is that the 'Fuji strips' were shot in a Canon T90 with an FD 50/1.8 while the 'DIY strips' were shot in a Canon EOS 30v with an EF50/1.8. There can be color differences due to differences in coatings of these lenses.

Here's the same thing without the lightness correction for the underdevelopment of the DIY strips:

Here's the raw scan:

If you look at the real world garden shots, there's an overall color difference on esp. the blue channel. Like I said, it could be the lens coatings, it could be the chemistry - I really don't know, but I assume it's mostly because of the chemistry and in particular I expect that the pH for the DIY mix ended up too low. What I don't see is a very dramatic difference in color balance (just in absolute density); it's quite subtle if you correct for the underdevelopment. I bet that if I had properly controlled the pH on the DIY chemistry, they would have come out pretty close. But I can't tell for sure.

If I hadn't done the comparison and would have just had the DIY-processed negs to work with, I likely never would have noticed anything particular about them. Those negatives will print just fine onto RA4 and they scan fine, too. Are they 100% the same as the Fuji-processed strips? Evidently not. The question is at what point the difference becomes a problem.

 

[Wayne]

FYI, this is the source I quoted: https://fotofilmfabriek.nl/product-categorie/fotochemie/kleurenontwikkelaar/c-41-kleurenchemie/



Btw @Wayne sorry if the above sounded a little terse, but your 'problem' seems like one that's also a matter of mentality. If you want to shoot color film, it's going to cost you, one way or another. Nobody can sweeten that deal, ultimately.

Yes it did sound that way, but I've come to expect it from Photrio which is why I haven't been here in years. Nice to see it coming from the mods now too.

 

[ags2mikon]

Ouch! That's going to leave a mark.

 

[Wayne]

Unfortunately, an expensive pH meter is essential if you want to achieve decent results with DIY chemicals. Even the slightest difference in the pH of the developer solution can cause problems with contrast or color reproduction (especially red). This has been mentioned many times, probably even in this thread. You can buy a cheap pH meter, but it will likely break down quickly and could ruin a negative that could be very important to you. With C-41 developing, if something goes wrong during bleaching, you can bleach again. Similarly, you can use fresh fixer again to fix what was messed up by the wrong or expired chemicals. But you can't fix a badly developed film. I mean re-developing in the correct developer will not help. This will frustrate you and discourage you from further experiments.

Pretty clear that a cheap pH meter CAN work, for a while, as long as you continue testing/calibrating it for drift which seems like a doable thing. But since the DIY won't give the same quality results as commercially available products I will pass on it. I'm interested in results, not experimenting, though I will follow others experiments.

 

[RPC]

If you plan to do your own processing into the future and can afford the initial investment, I think mixing your own from scratch chemicals makes sense.

You can save money in the long run mixing your own because the chemicals are all powders and last for years, especially if refrigerated or frozen. I have been mixing C-41 developer for more than 10 years and stocked up on the raw chemicals back then, so when I mix it today from these chemicals, I am paying yesterday's prices. I can mix only what I need when I need it. I don't have to worry about cost or availabilty of commercially packaged stuff today or in the future. I have observed no difference between the formula I use (PE's formula minus iodide and DTPA, mixing with distilled water) and Kodak C-41 developer. I have not tried Fuji. As I indicated in an earlier post, I need no pH adjustment with this formula, unlike other formulas.

Also, many of these same chemicals are used for b&w developer formulas and so I have them on hand for those, as I also do b&w.

Eventually I may need to re-stock, but over the long run will again save.

 

[Wayne]

If you plan to do your own processing into the future and can afford the initial investment, I think mixing your own from scratch chemicals makes sense.

You can save money in the long run mixing your own because the chemicals are all powders and last for years, especially if refrigerated or frozen. I have been mixing C-41 developer for more than 10 years and stocked up on the raw chemicals back then, so when I mix it today from these chemicals, I am paying yesterday's prices. I can mix only what I need when I need it. I don't have to worry about cost or availabilty of commercially packaged stuff today or in the future. I have observed no difference between the formula I use (PE's formula minus iodide and DTPA, mixing with distilled water) and Kodak C-41 developer. I have not tried Fuji. As I indicated in an earlier post, I need no pH adjustment with this formula, unlike other formulas.

Also, many of these same chemicals are used for b&w developer formulas and so I have them on hand for those, as I also do b&w.

Eventually I may need to re-stock, but over the long run will again save.

Well damn, now I'm tempted again, lol. But I will probably hold off for now. Prices are still good for CD-4 and HAS and I usually have just about everything else on hand.

 

[originalwinslow]

I'm back with a bit of an update.

To keep everything organized, the tests I have performed have been with the following 4 variations:

PE formula with RPC rounded amounts and omitting potassium iodide
PE formula with an accidental halving of the sodium sulfite
PE formula with potassium iodide
RPC simplified formula (sodium sulfite, potassium carbonate, KBr and CD-4) adjusted pH down from 10.9 (!) to 10.12 w/ 30% acetic

I have compared these to the "baseline" of factory-made CS developer (which I believe is repackaged Unicolor developer FWIW). I will say up top that these conclusions are based on a NLP conversion workflow. I have come to understand why @koraks warns against drawing conclusions from this conversion method, but since it is the only reasonable way for me to easily/consistently work with negatives I have to use it as my "real world application" baseline. Each conversion method will yield different results. Also, the manual conversions he was kind enough to work on exhibit similar characteristics. So there's the grain of salt and all that.

My first conclusion is that the CS developer definitely arrives off-spec. It has already experienced a certain amount of oxidization by the time it is mixed, which makes it a less-than-suitable comparison baseline. Alas, my options are limited. Second, the batches I have gotten recently have a far too high of pH upon mixing. 10.38. I contacted CS and they told me (in a strangely non-committal way) that the ideal pH is in fact 10.1. When I told them that their product was repeatedly off this mark they ignored me. Unimportant, but that shows how much they care about quality control. But we're not here to talk about CS or their shortcomings.

My HB variations all have small visible differences in the negatives, but these variances are ultimately smoothed out by the NLP conversion software. YMMV depending on the conversion method you use. The variance between the full-spec recipe and RPC's simplified version is quite visible in the negatives, but in the conversion these differences mostly disappear. Again, this is largely a result of the software interpreting the information, but since I likely won't ever be manually converting images on any large scale I'm just going to give myself over to the void and let the software do its thing. That's to say that in MY workflow the two recipes give almost identical results. I am not optically printing, so I have no information on how they may differ in that respect.

My HB variations all give cleaner results than the CS factory chems. Better color separation, whiter whites, deeper blacks, minimal color cast in shadows, crisper skin tones, more contrast. The variation with the potassium iodide gave me my favorite result, with the simplified RPC version being almost identical. So yes, omitting the iodide is mostly inconsequential.

That being said, the lack of saturation in the reds and greens when compared to the CS chems is noticeble. Greens in the HB just feel duller and slightly less true-to-life. Overall, as I previously mentioned, the HB results are cooler than the CS results. After a week of going back and forth between the images I think this is an overall point in favor of the HB.

I've included two converted images that I consider close to deliverable final products. CS vs HB V4 with iodide. I have made subtle edits purely on the density; no color tweaks besides what the software has already done. Not so much of a "true" comparison as it is an example of the result one can achieve using this HB formula and a similar digital workflow. I know there are certain color characteristics (such as the slight reddish color cast in the CS example) that are artifacts mostly from the NLP algorithm, while there are others that are inherent. So once again, grain of salt.

If there is interest I can post more comparisons of the negatives or individual scans for others to do their own lo-fi digital conversions. The usefulness of these comparison is limited by my access (lack theorof) to legit flexicolor developer and my stubborn dependence on the NLP software for conversions. I may be getting results identical to flexicolor and simply not know it. The CS developer could very well be the outlier here. So do what you will with this information.

I would like to dive deeper and find an empirical reason for the variations, although I am relatively satisfied with the HB at this point. I will likely try a new HB mix and see if there is a way to punch up the reds/greens. Maybe by raising the pH or adding more CD-4.

Or better yet, I could just convince myself that the higher saturation is objectively a negative characteristic and sail off into the sunset.

 

[ags2mikon]

Thank you for the update. Without using control strips and plotting the results this boils down to shooting in the dark. If it it works for you as is I think you should run with it. From what I have seen here I'm going to do the same. My father used to say when is good enough good enough?

 

[koraks]

My first conclusion is that the CS developer definitely arrives off-spec. It has already experienced a certain amount of oxidization by the time it is mixed, which makes it a less-than-suitable comparison baseline. Alas, my options are limited. Second, the batches I have gotten recently have a far too high of pH upon mixing. 10.38. I contacted CS and they told me (in a strangely non-committal way) that the ideal pH is in fact 10.1. When I told them that their product was repeatedly off this mark they ignored me.

This is interesting; I have always had some doubts about the Cs41 chemistry. In particular, I found it puzzling that they were apparently able to ship a powdered kit whereas no other manufacturer seems to have ever offered a commercial/professional powdered C41 option before. I'm not sure whether this has something to do with the pH issue, though.
Btw, I think why CS doesn't comment on your remarks is that they don't make the chemistry. For all I know, the party that makes it is...Kodak. If you take the Cs41 bags, there's an address somewhere on the back. You'll find it traces to Rochester, NY, specifically to one security gate into an industrial lot also occupied by Kodak.

If there is interest I can post more comparisons of the negatives or individual scans for others to do their own lo-fi digital conversions.

Always; you know (and have stated) my position on NLP conversions, so I always try a manual inversion on side-by-side scans/photos of the negatives to see what's going on.

Is there any way at all you might be able to procure some 'proper' C41 developer where you are? Surely, there must be a lab somewhere in Puerto Rico that processes color film? Maybe you can pinch a pitcher of developer form them - you know, 'for the cause', in exchange for a bottle of brew, and whatnot?

 

[Spektrum]

@originalwinslow you did a great job! Thank you ! I admire your commitment and determination.

I agree with @koraks that the ideal solution would be to find a source of "correct" chemicals, and the best solution would be a trip to a local laboratory and contact the owner. However, you need to get a fresh, ready-made replenisher + starter solution from them. Without the starter, you'll end up with the wrong chemicals again.

It's a shame we live so far apart, because to support your work, I'd gladly send you a separate replenisher and enough starter to mix 1 liter of working solution. Unfortunately, this isn't a shipping cost issue. It's a problem with regulations that make this impossible.

 

[Daniël Oosterhuis]

You can save money in the long run mixing your own because the chemicals are all powders and last for years, especially if refrigerated or frozen.

Just curious, what sort of storage containers or other storage methods do you use for the powdered chemicals, especially for cold storage? I've been interested in doing my own color developers, just for the fun of doing so, but making sure the chemicals don't lose their potency before they're used up is something that I'd want to figure out, as I don't like to be wasteful.

 

[koraks]

what sort of storage containers or other storage methods

Anything that properly seals and keeps the chemicals dry and for the developing agents, also dark. This can be glass jars with properly sealing lids, plastic containers (PP, PE), etc. It's really not very critical. It's the usual routine of 'store in a cool, dry place in the dark'. The color developing agent is quite stable; manufacturers mention something like 2 years but PE once told me that he had kept his around for decades and they were still A-OK.

 

[Spektrum]

I'm wondering if storing the key reagents (CD-3 and CD-4) in the plastic bags provided by the vendor is safe for these reagents.

I found a thread on Reddit where someone recommends pouring these reagents into brown (amber) jars. Here's a quote from that thread:

"Store it in an amber jar. You can get it in a 2oz, 4oz, etc., and wrap the top seals with electrical tape so it doesn't breathe. I stored CD-4 in a plastic bag like this, and it turned spotty; it's something about the bags that the chemicals don't like. I put sodium sulfate in a bag, and after a year of sitting (I was doing testing), it crystallized. CD-3 is the most sensitive to sunlight. I store mine in an amber jar within an opaque container in my closet. Always keep it away from UV light/sunlight, etc.."


Here's the link to the thread:


Of course, I store these color developer agents in the refrigerator, but in the plastic bags the seller delivered them in. I also wrapped them in black plastic wrap to prevent any light from entering when the refrigerator door is opened. The plastic wrap also acts as an additional barrier against moisture. I'm seriously considering buying brown jars, though, because there's probably no better way to store dry chemicals than in glass.

These key chemicals are currently readily available on eBay, but God knows how long they'll last and whether they'll ever disappear. I know they're available directly from the manufacturer (China) and can be purchased through Alibaba, but the minimum order quantity is one kilogram. Besides that, importing chemicals from China is a real challenge if you want to do it as a private buyer.

 

[koraks]

I'm wondering if storing the key reagents (CD-3 and CD-4) in the plastic bags provided by the vendor is safe for these reagents.

It depends greatly on the bags. Vendors use different bags; some probably use $0.01 LDPE zip lock bags, others use more sturdy zip locks, yet others use aluminum-lined heat-sealed pouches. I have some CD3 and CD4 that's stored in high-quality ziplocks that has been fine/unchanged for >2 years now. Most of mine I store in plain glass jars used for foodstuffs (e.g. olive jars). These general seal well and have a polymer lining along the metal lid that prevents corrosion of the lid. If these are stored in the dark, the glass doesn't have to be amber. I personally don't like amber glass if it can be avoided because it makes it harder to judge the color of the contents. Especially for developing agents it's really useful to be able to see whether spots and discolorations have developed. Clear glass jars make this easy to see.

God knows how long they'll last and whether they'll ever disappear

As long as there are commercial labs churning out film & paper that require CD3 and CD4 to process, some of the chemistry will continue to find its way to the consumer market, I'm sure.