C-41 in Jobo

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OK...So I want to experiment with C-41 processing 4x5 with my Jobo. I took advantage of Jobo's "first time buyer half-price" deal and ordered the Tetenal C-41 kit.

Now the instructions refer only to 35mm film, and say that you can process four batches for a total of twelve 36-exposure rolls - which implies 3 rolls per batch. And they give the time adjustment for each batch. I usually assume that 1 35 exposure roll of 135 ~= 4 4x5" sheets.

I also infer that the instructions assume that you are using the entire liter (litre) when processing a batch. The problem is that my tank really won't hold more that about 300 ml, and 270 ml is considered the minimum for proper coverage. (This is using one reel with a maximum of 6 sheets).

So what do I do? Can I develop in 300 ml and go one shot? Develop in 300 ml, pour the used developer back into the 1l batch and follow adjustment times. (Except that I have a max of 6 sheets per batch and a batch according to the directions would be more like 12.)

What if I want to run less than 6 sheets?

I would like to know what other do.

-- John H. Henderson (jhende03@harris.com), January 02, 2001


Hi John,

I also use jobo equipment, and do only one shot withthe minimum amount of solution and have good results. i use 120, 35mm, 4x5, and 2x3. Bill

-- Bill Jefferson (jefferw@together.net), January 03, 2001.


There are two thing to be concerned with: 1) the minimum amount of chemistry needed for the particular tank and 2) the maximum amount of film per volume of chemistry. Your assumption that 1 135x36 roll ~= 4 4x5 sheets is correct, the rest is simple math. Like Bill, I process 135 through 8x10 in a JOBO and always use the chemistry single shot - it works great.


-- Pete Caluori (pcaluori@hotmail.com), January 03, 2001.

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