Looking for C41 tips!

[ericantonio]

Hi guys,
Been developing B&W long time, even did it for a living for a while in NYC ... with inspection no less! (you are too young if you don't know what that is :) )

Anyway, delving into some c41 processing this week. Will start with some roll film and then eventually some sheet film. I usually do sheet film these days in my bathtub and trays. But I do have the square box thing that holds 4x5 and I 4x5 Nikor tank that I've never used.

Any tips you got for C41 for a newbie? I'll take some roll film tips and some sheet film tips in trays if you got them.

[RMiksell]

I process mine in 1 gallon stainless steel tanks (8x10) with hangers in a wash tub of tempered water in my garage (at night). I only do sheet film, agitate continuously for development. I have a fish tank aerator for the bleach. I start development at 102F and use the temp drifts down slowly throughout development. I've had good results darkroom printing to RA4 paper with the negatives. Development time and temp are most critical, other steps less so. Good luck, it's not any harder than developing black and white. I'm using Fuji chemistry (only need to add water).

[Bernhardas]

If you develop in a closed tank or drum, beware of the blix burp.
Depending on chemicals used, some recommend to immediately use blix after development without wash in between.
(For example the unicolor kit)
In this case the blix develops co2 that might blow the lid right of your drum or tank and cause spillage.
A wash with 2 water changes between developer and blix greatly reduces the burpiness.
But I nevertheless lift the cap after 1 minute and then every two minutes to let excess pressure escape.

[kaif]

Don't know if you have a processor like one of the Jobo units available. If not, I have found a simple kitchen sous vide immersion circulator a cheap way to get precise temperature control for processing roll film in Paterson tanks or similar (like the circulators here: https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dgarden&field-keywords=Sous+Vide+Thermal+Immersion+Circulator). I use one of these circulators together with a good lab thermometer as control reference, and this does allow me to hold the water bath pretty much within 0.1 degrees tolerance throughout the day without effort, and to keep chemicals and Paterson tanks at the correct temperature throughout processing. Of course the unit needs to have the right tolerance (0.1 degree) and cover the temperature range you want to use. It's possible that I might just have been lucky, but the circulator I bought for this turned out to be very temperature-stable.

Some people advise 'C-41 beginners' to start processing at lower temperatures than 102F, and some kits like Digibase give development times for this now. I guess the thinking here is that it takes some of the stress out of having to handle the turnaround times. Personally I never had a problem with this, and since you have been developing b/w for a long time, I very much imagine you will be fine with 102F from the start.

Unfortunately I don't have experience processing C-41 sheet film though, just C-41 roll film or 4x5 b/w sheet film (in dishes). I would be very interested to hear how others get on with processing C-41 in dishes, if anyone was going down that route. For b/w, I tried using 4x5 film holders like the MOD54 in a Paterson tank, and I don't get even results with these. So personally I don't think it's worth trying this for C-41, although of course others might have great results!

[kaif]

...one more thought: there are two different kinds of C-41 kits available, those which combine bleach and fix into a single blix bath, and those which have separate bleach and fix processing steps. I started with the first type, and then changed quite quickly over to the second type, mainly because the results I had with the blix were more grainy than I had expected, in particular with faster films. I do get better results regarding grain after switching to a process with separate bleach and fix. (There are very long online discussions about blix vs bleach / fix, which of course you might already have come across!)

[ericantonio]

This is awesome!!! Keep on coming. I've seen some people agitate in the begining only, some do constant, some do every minute. I'm sure one or a combination is correct. I'm guessing agitation doesn't affect the grain structure on color like it does B&W?

I bought the Arista kit for now just to get acclimated to the whole procedures.

As much as I prefer tray for B&W for 4x5 and 8x10, I'd probably use the Yankee or Nikor tank for the 4x5's.

[mitrajoon]

It's possible that I might just have been lucky, but the circulator I bought for this turned out to be very temperature-stable.

So which one did you buy?:confused:

[kaif]

The one I went for is a 'videmaster', at least that's what they are called in the UK. (The actual product page I bought it from is no longer up, but I think this is the same unit: https://www.amazon.co.uk/Videmaster-Cooker-Precision-Thermal-Circulator/dp/B06XCWLB1W/ref=sr_1_3?ie=UTF8&qid=1501691809&sr=8-3&keywords=Videmaster) Part of the reason I went for this one is that it can both be hung over the edge of the containing bath and stand quite solidly on it's own, which seemed like a good idea.

I find that I need to set mine at about 0.3 degree above the temperature I want to achieve in the chemicals bottles and processing tank. Over a full day of processing, I usually have to adjust this setting on the circulator by maybe 0.2 or 0.3 degree, to keep the temp inside the bottles / tanks constant. So it doesn't totally replace a proper lab thermometer and temperature checks, but it does make the whole affair very straight-forward. Of course, it will likely need some initial experimenting to find the settings which work best for each scenario, bath size etc.

[mitrajoon]

Kaif,

Thxs!