I tried Aerocolor C-41 Reversal: Very Odd Results

[Yezishu]

Recently I have some results. I used EI 100 with HC110 1:15 for 8 minutes at 38 degrees, followed by reverse exposure and C41 processing by myself. The image retains detail, there's no edge effect phenomenon that loccdor reported (To me, it appears only in cases of severe overexposure).

The problem: the slides (left) exhibit a significant magenta shift and lack green when compared to the actual scene (right), which I simulated using curve adjustments. My results are also somewhat inconsistent with some other reports on Aerocolor. Is there anyone who are familiar with the color reversal process can offer some suggestions on this? Since the C41 color developer is self-prepared, is it possible some pH problem?

 

[loccdor]

Thanks for showing it @Yeshizu. Harman Phoenix also has a red shift when processed with C-41 reversal, which is affecting the shadows more than the highlights. But this one appears to affect the highlights as well.

I have used C-41 developers for more than 6 months without color shifts as extreme as this, at least when doing normal C-41 negative processing. I hope someone with knowledge on this type of reversal can make recommendations.

 

[Bestia]

Recently I have some results. I used EI 100 with HC110 1:15 for 8 minutes at 38 degrees, followed by reverse exposure and C41 processing by myself. The image retains detail, there's no edge effect phenomenon that loccdor reported (To me, it appears only in cases of severe overexposure).

The problem: the slides (left) exhibit a significant magenta shift and lack green when compared to the actual scene (right), which I simulated using curve adjustments. My results are also somewhat inconsistent with some other reports on Aerocolor. Is there anyone who are familiar with the color reversal process can offer some suggestions on this? Since the C41 color developer is self-prepared, is it possible some pH problem?

View attachment 398318

I experienced a similar magenta cast with the same process on Aerocolor film.
Since the color development in the reversal process is to-complete, I believe the issue stems from the first developer not developing the three layers evenly.
I also noticed a slight magenta cast on Ektachrome 100D when I processed it using a black-and-white developer followed by ECN-2 at 38°C (the standard temperature for E-6). On my second attempt, I increased the temperature to 41°C, and the magenta cast disappeared.
So maybe the temperature of the first developer is the most important, I plan to try developing Aerocolor with a bw developer followed by C-41 at 41°C soon.

 

[Yezishu]

I experienced a similar magenta cast with the same process on Aerocolor film.
Since the color development in the reversal process is to-complete, I believe the issue stems from the first developer not developing the three layers evenly.
I also noticed a slight magenta cast on Ektachrome 100D when I processed it using a black-and-white developer followed by ECN-2 at 38°C (the standard temperature for E-6). On my second attempt, I increased the temperature to 41°C, and the magenta cast disappeared.
So maybe the temperature of the first developer is the most important, I plan to try developing Aerocolor with a bw developer followed by C-41 at 41°C soon.

Thanks for your information. Currently my photos still comeout with magenta color cast appearing in shaded areas as EI/CD time change, hope the temperature change can improve this point.
FD HC110 1:15, 8 min@38°C, followed by reverse exposure and C41@38°C.

• EI 50, C41 CD 3.5min
• 
• EI 100, C41 CD 3.5min
• 
• EI 50, C41 CD 5min
• 

 

[Bestia]

Great experiment!

In reversal process, color development should carried to completion, meaning all remaining silver halide is fully developed. The push/pull, color shift, and contrast primarily depend on the amount of silver halide LEFT after the first developer. Therefore, the first developer plays a dominant role in determining these characteristics. How much silver halide left, how much dye formed. Tweaking the color developer shouldn't have much impact. 5min in C41 got more D-max than 3.5min indicates 3.5min was not enough to make all silver halide developed, so 5min may give more consistent result.

The top layer (yellow coupler) undergoes the most development in the first developer, leaving less silver halide for color development, which results in reduced yellow dye formation and a blue cast. Adding some potassium iodide to the first developer could inhibit development in the top layer, maybe this could mitigating this imbalance. The first developer of a E-6 kit do have potassium iodide in it. However, the observed magenta cast, rather than just a blue one, suggests that the bottom layer (cyan coupler) is also overdeveloped in the first developer, leaving less silver halide for color formation. I can't imagine why bottom layer got more development than the middle layer, may be the aerocolor is made more sensitive to red ?

 

[Yezishu]

Thanks for all the suggestions, I confirmed that there is no problem with the C41 CD, and the color balance problem is due to FD.
After switching to another FD formula more similar to E6, the color balance of aerocolor 2460 has improved. Could it be due to the potassium iodide? I am not sure why HC-110(new version) behaves differently here.

First Developer:

• 5.16 g sodium bisulfite
• 0.1 g dimezone S
• 1.5 g hydroquinone
• 2.625 g sodium hydroxide
• 2.3 g sodium carbonate
• 3 g sodium bicarbonate
• 0.625 g potassium bromide
• 0.0125 g potassium iodide
• Add water to 250 ml

FD @ 38°C for 8:00, C41 CD @ 38°C for 5:15.
The colors are not accurate and the process is much deviating from the readily available HC-110 and C41. But at least it is "usable" for me today. EI 100 scan:

 

[Yezishu]

This time I use an manual E6 kit with 100 ISO(TTL) and an 85C filter. The blue color cast nearly vanished, likely due to a different processing formula than the lab's.
I might try using E6 FD with C41 CD to see how the test sample turns out. I'm not expecting much, but it could be interesting...

 

[Yezishu]

Recent results, I might take a break for a while to think about what to do next. Aerocolor has some potential, but the color cast issue as slide still needs to be further optimized.

It feels like if I can't use convenient concentrated solutions like HC-110 and have to do too much individual mixing and adjustment, or if I can't use standard C41 processing, it somewhat deviates from the original general-purpose intention....

As a reference:

EI 50~100, FD @ 36°C~38°C for 8:00~15:00. The solution deteriorates quickly, a test strip is needed before each use.

• 5.16 g sodium bisulfite
• 2.625 g sodium hydroxide
• 2.3 g sodium carbonate
• 3 g sodium bicarbonate
• 0.1 g dimezone S
• 1.5 g hydroquinone
• 0.625 g potassium bromide
• Add water to 250 ml

CD @ 38°C for 5:00~6:00, this formula is close to standard C41.

• 1.175 g anhydrous sodium sulfite
• 7.3 g sodium carbonate
• 0.48 g sodium bicarbonate
• 0.325 g potassium bromide
• 0.3 mg potassium iodide
• 1.3 g CD-4
• 0.625 g hydroxylamine sulfate
• Add water to 250 ml

EDTA bleach—improper bleaching can result in more reddish tint.