C41 Color Film - Reversal Process

[arturo_rs]

Hi!

I´ve tried an experiment. Is it posible to make slides with C41 color film using C41 chemistry?

Yes, it is. The result, better that expected.



The first problem is, as we know, color film has an orange base. So, the slides will have that orange tint. That was the main difficulty, try to eliminate or mitigate that.

This is important. This is how I remove halfway the orange base. I just used cyan filter from the kit the I use for enlarge prints.

• Orange Base + Cyan Filter:

This is the kit: https://www.freestylephoto.com/31633-Arista-RA-4-Color-Filters-3x3-in.-21-Pack

If you take the base of color film and add it the filter, the image is neutral. Example (made with Iphone 13):

• Neutral photo:

• With orange base film in front of the lens:

• With orange base + 50 cyan in front of the lens:

The more cyan added, the larger the correction is.



The second obstacle? This is the very first time that doing this process, I have no idea of the chemicals and times “recommended”. Is like to win the lottery.

How i shot it? The roll is Fuji 200 (not C200). Nikon camera and 50mm 1.8D. The scene was harsh light on a bright sunny day. February in South Spain. I shot it at 12, 25, 50, 100, 200 and 400 ISO. Every line of six photos has the same cyand filtration. So:

12 ISO + 0 Cyan	25 ISO + 0 Cyan	50 ISO + 0 Cyan	100 ISO + 0 Cyan	200 ISO + 0 Cyan	400 ISO + 0 Cyan
12 ISO + 40 Cyan	25 ISO + 40 Cyan	50 ISO + 40 Cyan	100 ISO + 40 Cyan	200 ISO + 40 Cyan	400 ISO + 40 Cyan
12 ISO + 50 Cyan	25 ISO + 50 Cyan	50 ISO + 50 Cyan	100 ISO + 50 Cyan	200 ISO + 50 Cyan	400 ISO + 50 Cyan
12 ISO + 60 Cyan	25 ISO + 60 Cyan	50 ISO + 60 Cyan	100 ISO + 60 Cyan	200 ISO + 60 Cyan	400 ISO + 60 Cyan
12 ISO + 70 Cyan	25 ISO + 70 Cyan	50 ISO + 70 Cyan	100 ISO + 70 Cyan	200 ISO + 70 Cyan	400 ISO + 70 Cyan
12 ISO + 80 Cyan	25 ISO + 80 Cyan	50 ISO + 80 Cyan	100 ISO + 80 Cyan	200 ISO + 80 Cyan	400 ISO + 80 Cyan

So, the chemicals. This is what I used and the times:

1º Developer: HC110 Dilution B (1+31) at 40ºC (104ºF) during 13 minutes – First minute continuous agitation, then 5 rotations every minute. In this step the tank is not moving. The temperature is mantained with a sous vide and a digital thermometer. IMPORTANT: The thank was also warmed up in the sous vide. Not prewashed.​

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2º Wash: 6 water changes. 300ml of water at around 40ºC, rotating each 30 seconds.​

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3º Fogging: The film, with the spiral, fogged with an LED 5,5W during 3 minutes at 20cm close. Room with little light from the window. Assure the light reaches all parts of the film.​

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4º C41 Developer: Normal dilution and time. Im my case, I used Bellini C41 so, 3:15 minutes at 38ºC (100,4ºF) rotating.​

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5º Stop Bath: Dilution of acetid acid, 30 seconds.​

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6º Wash: Just one, 30s seconds.​

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7º Bleach and Fix: For the bleach, Bellini says 1 minute, I did 3 minutes. For the fix, Bellini says 2 minutes, I did 5 minutes.​

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8º Final Wash. Personally, 8 changes of 300ml of water, rotating, each one 30 seconds.​

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9º Optional: Stabilizer.​

The results:

For me, very good results. The cyan filtration is noticeable, but the temperature of the photos is a little bit cold. Maybe adding a light yellow filter (that the kit has too) i get a warmer photo. The exposure, ISO 100 or 200. It depends of the light situation.

Full res:




I like the 100 ISO + 80 cyan version (sixth lane, fourth photo) and I think that i should increase the filtration to eliminate more of the orange base in the future. I don´t know if I will make a continuation is this “project”. I am sorry but i can´t scan the photos a better way. In reality it looks way better.

I would like to read your comments.

 

[Quiver2]

A very interesting project you have here and answers something that I was wanting to try out soon myself. Have you considered trying one of the various repackaged aerocolor films with the largely transparent base? I think that would make for much better slides using this process.

 

[arturo_rs]

A very interesting project you have here and answers something that I was wanting to try out soon myself. Have you considered trying one of the various repackaged aerocolor films with the largely transparent base? I think that would make for much better slides using this process.

Yeah, maybe the maskless film helps to reduce the orange cast to a lighter one.

About what I wrote before, adding more cyan and yellow is going to improve the images.

If someone wants to the send me film to make tests, I will make them and publish the results much faster.

 

[koraks]

The 'maskless' films are indeed easier to balance to a somewhat neutral result. Aerocolor IV has a pinkish base, and Harman Phoenix is kind of cyan/blueish. The Aerocolor is probably closer to neutral and I think it's also cheaper in 35mm cassettes than Phoenix (not to mention Phoenix is in short supply to begin with).

 

[arturo_rs]

The Aerocolor is probably closer to neutral

Surely you know more than me of these topics. If I take this challenge, to shot Aerocolor…any recommends?

 

[koraks]

I've never tried reversal processing it, and the only Aerocolor I've shot so far was a few sheets of 4x5". It worked pretty much like any other color negative film, but without the orange mask. The colors are slightly weird as well, but it's only subtle.

Why not get a roll or two and try a small part? When doing such experiments I usually take a roll of 35mm, snip it in half or even in four equal parts and then experiment on those smaller bits until I've learned what needed to know.

 

[arturo_rs]

I've never tried reversal processing it, and the only Aerocolor I've shot so far was a few sheets of 4x5". It worked pretty much like any other color negative film, but without the orange mask. The colors are slightly weird as well, but it's only subtle.

Why not get a roll or two and try a small part? When doing such experiments I usually take a roll of 35mm, snip it in half or even in four equal parts and then experiment on those smaller bits until I've learned what needed to know.

Ok

 

[lamerko]

I'm currently testing film reversal as well, but a bit lazy. I use ECN-2 film and chemistry because it is significantly cheaper.
I'm not ready to post anything yet, but I've come to the following conclusions:
- the film must be overexposed. Maybe about two stops, but I'm still testing. In fact, this is logical - the positive image will be the reciprocal of the negative, a large compensation is needed.
- it all depends on the black and white processing. An overactive developer with low fog values is required. In this regard, many of the standard black and white developers are simply not suitable (not active enough), and also large dilutions will not be suitable. The high temperature of the developer is a given - this raises the activity quite a bit, but care must be taken not to produce fog.
- high contrast is needed. I would stir as vigorously as possible
- color processing has no critical places - it just has to be processed long enough there. Double development time is enough, leave more - there will be no problem.

 

[Bronson Dugnutt]

I tried something similar with Vision3 500T several years ago. Being a tungsten balanced film means you don't need to use any additional cyan filtering to counteract the orange mask when using it in daylight. I exposed it at ISO 100 and used an ECP-2 color developer which has curve characteristics that further act to 'mask the mask', as it were.

I too found that the results don't scan well but do look quite good when viewed in person with daylight illumination.

 

[halfaman]

One important thing is that mask density is not constant, it is variable and inverse to the developed image in CD. In this case the mask has maximum density in highlights and minimum in shadows. So it should be impossible to "remove" the mask preserving neutral colors, you may have to choose between pinkish highlights or cyaninsh shadows.

 

[koraks]

So it should be impossible to "remove" the mask preserving neutral colors, you may have to choose between pinkish highlights or cyaninsh shadows.

There's that. The other issue is that I'm not sure if the process of breaking down the masking dyes can be decoupled from the process of forming the image dyes. AFAIK both processes happen during development; I'm not sure if the mask destruction process is directly linked to the negative dye image formation process (e.g. the former using a byproduct of the latter). So from a practical viewpoint, the question is if it's technically feasible to destroy the masking dyes without affecting the image dyes. Frankly, I doubt it.

 

[Richard Man]

Would this retain the dynamic range of C41 film vs. E-6 slides? If so, that's one advantage right?

 

[arturo_rs]

Some Aerocolor rolls ordered. Tests are coming in a few weeks.

 

[Bronson Dugnutt]

Aerocolor is a great film in it's own right and does respond a bit better to reversal due to the clear(er) film base. Analog Resurgence has a video with some examples:



In his case a warming filter rather than additional blue/cyan produced more natural results when used at a box speed of 125. The ISO rating you choose as well as the precise chemistry used for processing will impact the final color balance as well.

Looking forward to your results, good luck and have fun!

 

[Romanko]

Very interesting. Thank you for sharing your results.

Gregory Davis made an excellent video on RA 4 reversal filters:

As always, he used a systematic approach to figuring out the optimal combination of filters.
While film reversal is different from RA4 paper you can certainly adopt his methodology.

From very little I know about reversal processing, the first developer is the most critical step. It controls the contrast and the color shift. I am not sure if HC-110 is the optimal choice here. You might experiment with other developers. The formulas for several processes like E-6 and B&W are available if you choose to mix your own.

 

[arturo_rs]

In his case a warming filter rather than additional blue/cyan produced more natural results

Yeah, but the blue cast is produced using E6 chemicals not C41. Using a warming filter (85b for example) and E6 chemicals...the results are very good.

 

[arturo_rs]

I am not sure if HC-110 is the optimal choice here. You might experiment with other developers.

I use HC110 because a have a bottle completely full and I didnt know what to do with it.

 

[Romanko]

In case you haven't seen it, there is a thread on cross-processing slide film in C-41:

How to (consistently) make positive E-6 transparencies with C-41 chemicals

So I have been chasing this idea of being able to process E-6 film in B/W developer and C-41 chemicals in order to create positive transparencies. I've been working on this process since sometime last year, and I think I finally have it perfected for almost all types of currently produced E-6...

www.photrio.com

There are examples of Kodak Gold reversal.

 

[laser]

I offer this caution from a film manufacturer's perspective. From time-to-time manufacturers make changes in materials and the processes used to manufacture films. These changes are carefully tested to make sure users will get the desired results in the recommended film process. Manufacturers do not test for cross processing. So the cross processing result may vary among film batches. If you cross-process don't depend on getting the same results with different film batches. You might be luck but some time your luck might run out. www.makingKODAKfilm.com

 

[arturo_rs]

In case you haven't seen it, there is a thread on cross-processing slide film in C-41:

How to (consistently) make positive E-6 transparencies with C-41 chemicals

So I have been chasing this idea of being able to process E-6 film in B/W developer and C-41 chemicals in order to create positive transparencies. I've been working on this process since sometime last year, and I think I finally have it perfected for almost all types of currently produced E-6...

www.photrio.com

There are examples of Kodak Gold reversal.

Thank you

 

[Meinrad]

Olá Arturo,

thank you very much for sharing your experiences.
I took your receipt to develop a phoenix. Its drying but images seem to be very underexposed. I suspect the first developer time too high - just a feeling, more when its dried and scanned,

cheers from lake of constance,

Meinrad

 

[Meinrad]

So, now i have scanned the roll, color settings neutral. The pictures are very dark and with a reddish shift, so i will try the next roll with less time for first developper (or lower temperature?) I was using Ilfotec HC 1:31 (same as HC110).

The second one was the first picture on the film, overexposed because of the fixed time of the F3, but i show it because you can see the colors are quite ok

 

[arturo_rs]

but images seem to be very underexposed.

For that I made a bracketing. I didnt know how it was going to look.

I suspect the first developer time too high.

On a few days i will shoot some aerocolor rolls. I think i will try a more diluted version.

 

[BHuij]

The 'maskless' films are indeed easier to balance to a somewhat neutral result. Aerocolor IV has a pinkish base, and Harman Phoenix is kind of cyan/blueish. The Aerocolor is probably closer to neutral and I think it's also cheaper in 35mm cassettes than Phoenix (not to mention Phoenix is in short supply to begin with).

I was pleasantly surprised by how much I liked Phoenix after my first roll, developed "normally" (or at least as a negative) using ECN-2 chemistry. The dynamic range is tiny though, so as someone who has not designs on RA-4 printing, it probably would make more sense for me to shoot it and reversal process in the future. Might give that a shot.

Thing is I just really like Ektachrome, and feel like a C-41 film reversal processed would disappoint me after having the real thing

 

[brbo]

I can understand reverse processing Phoenix to satisfy ones curiosity, but doing it because dynamic range is very limited even when processed in C-41?! Do you hope that dynamic range will somehow be better? And it's not like curves even in the current incarnation of Phoenix match. There is zero hope that it will look or scan better when reverse processed.