C41 Processing in a Paterson Tank, advice sought on Colour Developer step.

ChrisGalway said:

Perhaps rotary agitation using the twiddle-stick is OK? (I've always preferred inversion.)

Click to expand...

ChrisGalway said:

presumably there is much more latitude in C41 (negative film processing) compared to E6 (transparencies).

Click to expand...

koraks said:

I routine process CN film in a Paterson tank. Much of the time I don't want to bother with getting the Jobo processor from storage, so I just use the Paterson tank instead. I generally keep it in a tempered water bath prior to and during development. Agitation I simply do as with B&W: manual inversions every 30 seconds. 2-3 quick inversions per cycle is more than good enough; this takes 2-3 seconds. You could do a cycle every 20 seconds if you're concerned about evenness, but I've never found it to be an issue with my normal 30-second cycle.

It helps to bring the tank up to temperature with a tempered pre-soak; just pour in and set the tank in the tempered bath for a few minutes. This prevents the developer from 'cold shocking' as it hits an untempered tank.


That works as well, but I virtually always do manual inversions. If you use the twiddle stick, don't be gentle. Remember it's agitation we're talking about. You're not trying to steal the pillow from underneath your sleeping wife's head. It doesn't have to be gentle. Heck, it's not supposed to be.


Yes, that too, especially if you scan, but also if you optically print there's a reasonable margin for error, unless you're trying to run a process with absolute 100% repeatability and color matching across consecutive rolls. I've yet to run into the first person who has a convincing use case for that in the 21st century, so I'm going to guess that you can get away with a little drift left or right. Unless you're doing densitometry on the film, you won't notice.

Click to expand...

blee1996 said:

C41 is not THAT sensitive, you should be able to do it without sweating. I do it in Paterson tank as well, and use sous vide to control water bath temperature. I also pre-soak the film to get the tank temperature up to 100F (38C).

Click to expand...

dcy said:

As it turns out, I am planning to develop C-41 for the first time this weekend and I am irrationally nervous about it.

Click to expand...

koraks said:

IDK, 3 seconds or so?

Click to expand...

ChrisGalway said:

Thanks, very helpful. How long does it take you to seal that Paterson lid, "burping" it? Perhaps my 30sec securing it is overkill ... the colour developer is just sitting there in the tank whilst I'm securing the lid.

Click to expand...

1. Left hand on the center of the lid.
2. Lean forward, putting my body weight on the lid to "burp" it.
3. Right hand presses down on the edge of the lid closest to it.
4. Lean back and rotate the tank > 90 degrees.
5. Lean forward again, repeating steps 2,3,4.
6. Repeat the steps again.

ChrisGalway said:

And to think that all these years I've been putting the Paterson lid on wrongly! I think this is a good way to... and yes, it should only take 3 secs:

Click to expand...

ChrisGalway said:

And to think that all these years I've been putting the Paterson lid on wrongly! I think this is a good way to... and yes, it should only take 3 secs:

Click to expand...

ChrisGalway said:

Motivated by another Thread on the virtues (expressed by some) of shooting colour negative film ... instead of digital ... I'm going to give colour negative film a try in a MF camera, processing the film myself.

But I see that the Colour Development time in C41 is just 3min15sec at the recommended temperature of 38degC. That seems very short and it seems to me it means that the method of agitation might be important. I'm used to E6 processing 120 film where the typical First Development time is 7-8mins, so after pouring in the solution, I can take my time securing the lid of the Paterson tank to make sure it's leakproof (20-30sec) and then doing my normal 12 inversions, once every minute (so securing the lid and doing 12 inversions takes up the whole of the first minute). But if I follow this for C41, that one minute is a large fraction of the 3min15sec total time. I understand that lower temperatures (and longer times) can be used, but surely that is not optimum.

I'm looking for practical advice to carry out the Colour Development. Perhaps rotary agitation using the twiddle-stick is OK? (I've always preferred inversion.)

Perhaps I'm worrying too much, because presumably there is much more latitude in C41 (negative film processing) compared to E6 (transparencies).

Click to expand...

Samu said:

My recommendation is using some other tank instead of Paterson's. For instance, filling and putting the cap on the JOBO 1500 series tank takes just seconds. For increased accuracy in C-41 hand processing, I use a stop bath. The older Paterson Koraks is referring to, works also fine. Personally, I don't like the "new" Paterson tank at all. It will always leak (at least when submerged to water bath). I don't want to remember how many batches of color chemistry I destroyed in the 80's and 90's because of the lid opening accidentally in the middle of the process.

Click to expand...

ChrisGalway said:

Well I have two Paterson tanks already, and process mainly 120 film using the AP Reel which is so easy and fast to load in a changing/dark bag. I can see that the Jobo 1520 tank is a premium product ... but does the AP Reel fit inside?

I've only just purchased a pack of CN film, so it's a few weeks before I actually do the C41 processing. The responses here have convinced me that it should be straightforward (given I've done a lot of E6).

Click to expand...