Processing C41 film as slide in b/w developer and C41

Slides are fascinating, but they are expensive, so I decided to try developing C41 negative film as slides. Since I don't own E-6 chemistry I thought of doing it with the alternative method mentioned in the title. But I'm not here to talk about the why, but the how. This is a fairly common process but as far as I know not all the possibilities have been explored.

So these are the steps:
1) Take the photo
2) Process in B/W developer (no fix)
3) Expose the film in room light
4) C41 color developer
5) C41 blix
6) Wash
7) C41 stabilizer
Expected result: slide with a prominent orange cast.

With the following precautions:
a) Step 3 must fog completely every layer of the film, so there is a minimum exposure needed, also, uv ligth might damage color couplers so I guess there is an upper limit too, but nothing too hard.
b) Step 5 the film needs additional time in blix bath. Apparently overblix is not a thing so I guess the longer the better (many state 15min is enough). Also if it was not enough, it can be fixed simply by repeating this step afterwards.
c) Step 4 I found two ways of doing it: the standard way, just use regular cd time; and this one: decrease time (and overexpose) to minimize the orange cast of the final result.

What I did:
-On Lomo CN100 took 6 photos with the following exposure compensation: 0,+1, +2, +3.
-Rodinal 1+50 20°C 20min agitating 5 times in 5min intervals.
-Hung the film while I was cleaning the tank.
-"regular"(I messed up a bit with temperatures but the control film came out nice) C41 process. I used Axelcolor Newbies 3 bath kit.
-Dried the negative and scan.

My results:
a) The best shot was the most overexposed.
b) The densest layer was the red one, the least dense layer was the blue, and green as in the middle. I guess this is also due to the developer having difficulty to filter through all the layers (Maybe this is not the case?).
c) The best shot (with an embarassing amount of editing):

d) The resulting film (left with corrected backlight and right white backlight):



My unsolved questions:
-Does reducing color developer time really improves the result?
-Is overexposing really better or you could get better images exposing at box speed, changing b/w developer time? In short, the only two variables are b/w developer time and exposure (ignoring the shorter cd method), what is likely to be the best combination?

Conclusion:
Of course the best result comes with the standard process. I really had a lot of fun with this experiment and liked the results very much. Might repeat it in the future (with your suggestions). I recommend it for who wants to try something different.

Hope you enjoyed my thread! I apologize for any English errors.

I've seen many examples of cross-processing the other way -- E-6 film in C-41 chemistry, which produces color negatives that print/scan with a heavy cyan cast (due to lack of the orange mask) -- but this is the first time I recall seeing C-41 film reversed this way.

I do recall reading that ECN-2 films (like the ones Cinestill sells with the remjet already removed) can be processed with a direct positive process (ECP-2, I think). It works much like what you've done here, but of course is optimized for those cine films with their slightly different emulsions.

My guess is that using C-41 chemistry instead of E-6 gives better results since it's the right one for the film, but maybe I am wrong. Also "better results" depends on the intended use for the film, because I tried projecting mine but all I got was an orange image on the wall.

@Ranieri Keep in mind that E6 FD has thiocyanate, so it helps clear the highlights. This might be the reason why overexposed shots might look better. One other thing you could do and will improve things a bit is use a cyan filter when shooting. When I tried a process like yours I didn't have a cyan filter, but tried an 80A anyway. These were better than the unfiltered ones, although the orange mask was overwhelming anyway.

Thank you, l'll give it a try with my cheap filter. My doubt still remains, is reducing cd really helpful to clear the highlights?

Ranieri said:

Thank you, l'll give it a try with my cheap filter. My doubt still remains, is reducing cd really helpful to clear the highlights?

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I wouldn't reduce CD time, I'd make FD stronger, perhaps use Rodinal 1+25 instead of 1+50.

If you think the effect of orange mask all the way through, then regardless of development you will have dense slides. These highlights won't clear up (@Anon Ymous !), because "highlights" in C-41 materials mean "orange mask". If you look at these overexposed slides giving "more natural colors": they still have this color cast (that's the nature of orange mask after all! ), it's just hidden behind excess density and therefore less obvious.

If you want "slides for scanning", because let's be honest, most scanners are really bad at scanning negatives, then develop according to Anon's recommendations: boost FD contrast through extended dev time, higher concentration and/or additional KSCN. Develop CD to completion: incomplete CD will give you incomplete shadows, which look "artistic".

If you want "slides for projection", then find C-41 material without color mask. It's out there.

@Rudeofus Ah, what I meant was clearer highlights, obviously not clear as in E6 clear, there's no way to remove the orange mask. Ranieri's bracketed shots show much denser highlights at box speed.

Rudeofus said:

Develop CD to completion

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I had thought of this because it makes a lot of sense, but, how long does it take? Are there suggested times for developing with cd to completion?

Ranieri said:

I had thought of this because it makes a lot of sense, but, how long does it take? Are there suggested times for developing with cd to completion?

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There are given times for E-6 film processed in E-6 CD, but obviously not for your setup. You are basically out on your own. You can try the following test:

1. Take film clips in regular room light.
2. Develop short test clips in this color developer for varying time: 3 minutes, 5 minutes, 8 minutes, 12 minutes
3. wash, BLIX and wash
4. Then measure density (don't need a professional densitometer, any film scanner plus vuescan can do this). You minimum CD time is the time it took to reach maximum density.

About the FD, i don't know how much different is a C41 film compared to E6,
but for a E6 film i used something like Rodinal 1+10 plus 2gr KSCN/L, 35-37C, 6:30mins.

DareFail said:

About the FD, i don't know how much different is a C41 film compared to E6,
but for a E6 film i used something like Rodinal 1+10 plus 2gr KSCN/L, 35-37C, 6:30mins.

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The biggest difference between C-41 and E-6 film are the former's DIR couplers. These will react with oxidized color developer molecules and create very powerful restrainers, and these restrainers will clamp down contrast. But you want contrast in reversal processing. So your FD must contain development agents, which do not couple. PPD and its derivatives in FD are obviously not an option. There have been reports, that oxidized p-Aminophenol will also react with couplers, therefore I would not use Rodinal either. I haven't heard, that oxidized Metol would couple, after all it has been used in older FD formulas.

Therefore I would pick some high contrast developer based on MQ, PQ or PC dev agent combos.

Rudeofus said:

Therefore I would pick some high contrast developer based on MQ, PQ or PC dev agent combos.

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Excuse my ignorance, could you please cite some developers like this?

When I was working at a photo lab processing film, I experimented with cross-processing C-41 films in E6 chemistry.
I found that a 3-stop Push was necessary to build sufficient image contrast...so it might help to extend your B/W development time, or maybe use a more concentrated/more active developer.

Ranieri said:

could you please cite some developers like this?

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Dektol (or D-72, if you prefer to mix your own) is a classic high contrast MQ developer (and largely the go-to first developer for B&W silver image reversal). Ilford MQ Universal is similar. Substitute sodium carbonate for borax in Mytol (likely with some adjustment of amount and buffers) and you'd get a high contrast PC developer.

FWIW, Kodak's commercial E-6 system uses an MQ first developer, though I believe it's buffered to a slightly lower pH than Dektol -- might be in the borax/Kodalk range. There's probably a good reason for this (and lack of other choices isn't it -- E-6, from 1976, is new enough that phenidone was well known (phenidone or a close relative is found in HC-110, which dates from 1962).

Donald Qualls said:

FWIW, Kodak's commercial E-6 system uses an MQ first developer, though I believe it's buffered to a slightly lower pH than Dektol -- might be in the borax/Kodalk range. There's probably a good reason for this (and lack of other choices isn't it -- E-6, from 1976, is new enough that phenidone was well known (phenidone or a close relative is found in HC-110, which dates from 1962).

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It's a Dimezone-S, Hydroquinone Minosulfonate potassium salt developer. The VNF-1 process used a PQ developer.

Okay. I'd have sworn there was an MQ first developer, but maybe it wasn't Kodak.

Donald Qualls said:

Okay. I'd have sworn there was an MQ first developer, but maybe it wasn't Kodak.

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Yes, there are several alternative E6 formulae floating around, the Zone V FD formula is what you have probably seen.

Following (not really) your suggestions, I made another attempt using XT-3 (Xtol) as FD. I bracketed with and without cyan filter (cokin 050) and used two different films: Lomo CN100 (as before) and Washi X (Kodak Aerocolo IV as far as I know).

These are the times (everything was developed at the same time):
-XT-3 Stock 15min 20°C
-CD 9min 38 °C (I still need to determine the exact time for developing to completion)
-BLIX 15min 38°C

These are the results:

Lomo CN100
1: +0 stop, no filter
2: +0stop, 1 cyan filter
3: +0 stop, 2 cyan filter
4: +2 stop, no filter
5: +2 stop, 1 cyan filter
6: +2 stop, 2 cyan filter
Washi X
7: +0 stop, no filter
8: +1 stop, no filter
9: +0 stop, 1 cyan filter
10: +1 stop, 1 cyan filter

My oservations:
all these photo scan really bad (I'll let you know which ones are the less bad when I am done scanning).
Washi X was really disappointing, but for sure it does not need the filter, I don't know what I did wrong there.
The leaders are almost identical in Rodinal/Xtol development, so I guess that Rodinal doesn't affect in a significant way colors.

So, what did I do wrong with Washi X? How can I get decent slides with it?

Ranieri said:

-XT-3 Stock 15min 20°C

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Why do you insist on developing in 20°C instead of 38°C?

DareFail said:

Why do you insist on developing in 20°C instead of 38°C?

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All the colour part of the process is done at 38°C.
Kodak Xtol datasheet does not list times above 27°C. I am afraid that increasing FD temperature could interfere with the chemistry. What I am saying is that I choose temperature based on the chemistry, not the film. Also raising chemistry temperature to 38°C is so frustrating that I try to avoid whenever possible. Genuinely asking, is there any evidence that developing C-41 film in Xtol at 38°C gives better results in any circumstance? I understand it can help with increasing contrast, but that can be achieved also in other ways.

Ranieri said:

Kodak Xtol datasheet does not list times above 27°C

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Does Kodak list times for Xtol to use it as first developer for developing c-41 film as slide?

When your best shots are the overexposed ones, this tells you something.
Try 6,5 mins 38°C at box speed.
You may never get a perfect slide. You are doing experiments.

DareFail said:

Try 6,5 mins 38°C at box speed.

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Done. My sincere apologies for doubting. By far the best results I got. Xtol stock 6,5min 38°C, light, CD 12min 38°C, BLIX 15min 38°C.

No filter was used.

Great. Maybe it needs 7 or 7:30 minutes or maybe you'll never get the clear highlights without KSCN added, no matter the time on the first developer.

I don't know why the CD has to be more than 6 mins. An expert could answer to this please.

DareFail said:

Great. Maybe it needs 7 or 7:30 minutes or maybe you'll never get the clear highlights without KSCN added, no matter the time on the first developer.

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My guess is the second one. One thing I noticed scanning is that the colours are very low saturation compared to the results of Lomo cn100, especially green.

DareFail said:

I don't know why the CD has to be more than 6 mins. An expert could answer to this please.

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In post #7 Rudeofus said to develop CD to completion. Because it's a bit complicated for me to determine the exact completion development time I just do random very long time, maybe times too long are detrimental?