Aerocolor IV - C41 Reversal Process

[arturo_rs]

Aerocolor IV – Reversal Process​

This is the continuation of this post. If you didn’t read it, I recommend you do it:

https://www.photrio.com/forum/threads/c41-color-film-reversal-process.205230/post-2774458


Well, after a few weeks new test are here. This time, Kodak Aerocolor IV. This is the datasheet for more information about this film:

https://www.kodak.com/content/produ...EROCOLOR-III-Negative-Film-2460-datasheet.pdf


So, let’s start it.


I did 2 tests. The first one with the same chemicals, temperatures and times from the other post:

https://www.photrio.com/forum/threads/c41-color-film-reversal-process.205230/post-2774458

From left to right: ISO 64, 80,125,160,200 and 250.

The results: I did not use any correction filter and the results…acceptable, much better than using c41 film with the orange base. The photos show some interesting things. The base (top and bottom perforations zone) shows a dark green cast. The 64 ISO (left) shows a little green cast, almost inappreciable. As the exposure increases the green turns into a magenta (right photos). I have to say that the photos were taken on a cloudy morning with some fog.



So, seeing the results a made some “energetic” changes. The red color shows what i did. Basically, HC110 dilution A and extend the C41 Dev plus 15 seconds.



1º Developer: HC110 Dilution A (1+15) at 40ºC (104ºF) during 8 minutes – First minute continuous agitation, then 5 rotations every minute. In this step the tank is not moving. The temperature is maintained with a sous vide and a digital thermometer. IMPORTANT: The thank was also warmed up in the sous vide. Not prewashed.


2º Wash: 4 water changes. 300ml of water at around 40ºC, rotating each 30 seconds.


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.


4º C41 Developer: Normal dilution and time. I used Tetenal C41, 3:30 minutes at 38ºC (100,4ºF) rotating. I extended the time 15 seconds more than recommended.


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


6º Wash: Just one, 30s seconds.


7º Blix for a total of 8 minutes.


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


9º Optional: Stabilizer.



This time the results are way better. Color pops and have a higher contrast. I have to say that were shot on a Nikon F70 at 80 ISO. Some photos are overexposed and all of them have a thing in common, the shadows are a little bit magenta, just subtle. The other thing, the whites are a little pinkish due to the base, also, just subtle.

I am going to do a last test making some changes. First one, bracketing (-0.3, 0, +0.3) and reduce the developing time of HC110 from 8 minutes to 6 minutes.

 

[koraks]

Quite interesting; the magenta color in the second set seems consistent with the base color on this film, so that looks OK. You could try and add some color filtration during exposure to shift it towards green a bit in an attempt to neutralize it.

I extended the time 15 seconds more than recommended.

Since this is the color development step, don't hesitate to let it run to completion. 5-10 minutes should be OK. Err to the long side; it doesn't make much sense to leave much undeveloped silver halide in the film after the first developer and bleach.

 

[arturo_rs]

You could try and add some color filtration during exposure to shift it towards green a bit in an attempt to neutralize it.

Yes, I think I´m going to do that.

Since this is the color development step, don't hesitate to let it run to completion. 5-10 minutes should be OK.

Increasing 3:15 to 5 minutes won´t make the photo more contrasted?

 

[koraks]

Increasing 3:15 to 5 minutes won´t make the photo more contrasted?

It might, but technically, it shouldn't. In general you control contrast in the first developer, not the color developer. In a regular reversal process, the color/second developer goes to completion.
You can of course control contrast with the second developer as well, but it comes at the cost of reduced dmax. Since C41 film is made to have lower dmax than E6 film to begin with, I wouldn't pick this route unless there's a very good reason for such a compromise.

 

[arturo_rs]

It might, but technically, it shouldn't. In general you control contrast in the first developer, not the color developer. In a regular reversal process, the color/second developer goes to completion.
You can of course control contrast with the second developer as well, but it comes at the cost of reduced dmax. Since C41 film is made to have lower dmax than E6 film to begin with, I wouldn't pick this route unless there's a very good reason for such a compromise.

So, if i want to reduce contrast I have to, for example, reduce the dev time with HC110. OK.

Thank you.

 

[arturo_rs]

Quite interesting; the magenta color in the second set seems consistent with the base color on this film, so that looks OK.

By the way. The pinkish tint is more pronunced in the photos with the digital camera. In reality is very subtle.

 

[koraks]

So, if i want to reduce contrast I have to, for example, reduce the dev time with HC110. OK.

Thank you.

Yes, and maybe change exposure as well. You'd have to experiment a bit.

The pinkish tint is more pronunced in the photos with the digital camera. In reality is very subtle.

I expected so, yes. The pink base is quite subtle on this film. I think it lends itself quite well to this purpose!

 

[Josaw98]

excellent job! I was looking for information on Dmax and stumbled upon this thread coincidentally. So I'm not going to delay too much, 2 things, first, the stop bath after the color developer is unnecessary, rinsing with water will be more than enough to move on to the blix, second, a stop bath is necessary after the first developer, the Water by itself does not work as a stop, that is where you should use your acetic acid solution and not in the color developer. A 1% solution of acetic ISO is sufficient for a stop bath.

2º Lavado: 4 cambios de agua. 300ml de agua a unos 40ºC, rotando cada 30 segundos.

 

[arturo_rs]

excellent job! I was looking for information on Dmax and stumbled upon this thread coincidentally. So I'm not going to delay too much, 2 things, first, the stop bath after the color developer is unnecessary, rinsing with water will be more than enough to move on to the blix, second, a stop bath is necessary after the first developer, the Water by itself does not work as a stop, that is where you should use your acetic acid solution and not in the color developer. A 1% solution of acetic ISO is sufficient for a stop bath.

OK, I will take it into consideration.

 

[arturo_rs]

As I said, the pink on the whites is very exagerate on the scans. Seeing it in real life is very subbtle.