Advice for a Newbie to C41 Processing

[russljames]

I have decided to try my first go with a C41 one liter kit. I will be using a Paterson universal tank. I have two questions:

Is it possible to increase development times and use developer/blix chemistry at room temperature and get usable negatives or must I use the 100 degree method? Directions in these kits show that one can develop at room temp with rotary type tubes. If it can also be done at room temp with my Paterson please advise on the appropriate times to use and any special agitation techniques that might be needed.

Also, would you recommend getting a new Paterson tank specifically for color work, or can I go between color and black and white chemistry with the same tank with thorough rinsing?

Thanks for any advice you can give me.

 

[Mike Richards]

I got the Tetenal C-41 kit, and it has an alternate method for 86F instead of 100F. I've tried both temperatures, and can see no difference in the results. I use stainless steel tanks and have no problems for conventional B&W and C-41. If you keep it clean, I expect the Paterson would work ok for both, but I hope someone with actual Paterson experience will chime in on this.

 

[Ian Grant]

The C41 dev times etc are short and it's really easy to process at the recommended temperature. use a bowl and a kettle of water as a water bath (the kettle to add hot water as needed), so there's little point using a lower temperature.

As long as you wash the tanks well there's no need for them to be dedicated to ant particular process.

Ian

 

[srs5694]

I've heard from reliable sources, such as a former Kodak chemist who posts here as "Photo Engineer," that developing C-41 at anything other than the specified temperature will result in color shifts that won't be 100% correctable when printing. You might get close, but it won't be quite perfect. That said, I've not attempted to study this myself; I can only pass on what I've read here and elsewhere.

A water bath is not all that hard to use. Get a big enough container, fill it with water at slightly above the target temperature, put your prepared bottles of photochemicals in the container, and wait a few minutes. I generally put everything in the water bath before I load my tank, and by the time I'm done loading my tank, the temperatures are at least approaching the target. It may be necessary to dump some water from the water bath and add more at a higher or lower temperature at this point. Some people use water heaters for more precision in controlling the water bath's temperature, but I've never done this myself.

 

[russljames]

Thanks for your great input. I have been convinced that doing this at the recommended temperature will not be difficult to do, and is the best way to proceed. Best of all, I don't need to spend more money on a new tank.

Russ

 

[hrst]

You don't even need a water bath. 3'15 is so short that you can average it at 100F. Test with water first. Start with 102F, if you end up with 98F after 3'15, then it's good to go like it. Adjust to get proper average.

It's probably better to do at "about 100F" even if it dropped a bit, than to use much reduced temperatures.

Bleach and fix (or blix) do not need exact temperature control, but as their times are longer, you might still want to consider using some kind of water bath - but it doesn't need to be exact!

 

[russljames]

I have also been advised to develop as many rolls as I can once chemistry is mixed as oxidation will occur rapidly. My test rolls will be from expired film (that has given good results from photo labs) now kept in the freezer. It may take a while to shoot six or eight of them. Any problems with putting exposed rolls back into a cooler environment after I shoot them?

 

[hrst]

No, oxidation won't occur so rapidly. Even with partly used solution, you can expect a shelf life of at least a month or so in bottles with all the air squeezed out. In fact, I have had great results even with solutions with age of several months, but it cannot be 100% promised.

 

[srs5694]

Refrigerating exposed film should be fine if you can't develop it immediately for whatever reason. The one possible catch is that condensation can theoretically form on the film and cause problems. This is obviously most likely when it's humid out. That said, I can't recall ever seeing a post or sample photo claiming or demonstrating problems caused by condensation of film caused by refrigeration or freezing, so I doubt if this is a big problem in reality.

 

[russljames]

Thanks, Rod. I shot almost one roll today. I have decided that they will be going back into the cool until ready to develop.

Russ